the Properties & 64bit region commit

git-svn-id: svn://localhost/ardour2/branches/3.0@6695 d708f5d6-7413-0410-9779-e7cbd77b26cf

107 files changed, 2627 insertions, 2141 deletions

diff --git a/gtk2_ardour/add_route_dialog.cc b/gtk2_ardour/add_route_dialog.cc
index 47eeb94320..18792bb654 100644
--- a/gtk2_ardour/add_route_dialog.cc
+++ b/gtk2_ardour/add_route_dialog.cc
@@ -414,7 +414,11 @@ void
 AddRouteDialog::group_changed ()
 {
 	if (_session && route_group_combo.get_active_text () == _("New group...")) {
-		RouteGroup* g = new RouteGroup (*_session, "", RouteGroup::Active);
+		RouteGroup* g = new RouteGroup (*_session, "");
+
+		PropertyList plist;
+		plist.add (Properties::active, true);
+		g->set_properties (plist);
 
 		RouteGroupDialog d (g, Gtk::Stock::NEW);
 		int const r = d.do_run ();
diff --git a/gtk2_ardour/audio_region_editor.cc b/gtk2_ardour/audio_region_editor.cc
index 3d29ed6b47..668ed8ed52 100644
--- a/gtk2_ardour/audio_region_editor.cc
+++ b/gtk2_ardour/audio_region_editor.cc
@@ -152,7 +152,7 @@ AudioRegionEditor::AudioRegionEditor (Session* s, boost::shared_ptr<AudioRegion>
 	show_all();
 
 	name_changed ();
-	bounds_changed (Change (StartChanged|LengthChanged|PositionChanged|Region::SyncOffsetChanged));
+	bounds_changed (PropertyChange (StartChanged|LengthChanged|PositionChanged|Region::SyncOffsetChanged));
 	gain_changed ();
 
 	_region->StateChanged.connect (state_connection, ui_bind (&AudioRegionEditor::region_changed, this, _1), gui_context());
@@ -167,13 +167,13 @@ AudioRegionEditor::~AudioRegionEditor ()
 }
 
 void
-AudioRegionEditor::region_changed (PBD::Change what_changed)
+AudioRegionEditor::region_changed (PBD::PropertyChange what_changed)
 {
 	if (what_changed & NameChanged) {
 		name_changed ();
 	}
 
-	if (what_changed & Change (BoundsChanged|StartChanged|Region::SyncOffsetChanged)) {
+	if (what_changed & PropertyChange (BoundsChanged|StartChanged|Region::SyncOffsetChanged)) {
 		bounds_changed (what_changed);
 	}
 
@@ -326,16 +326,16 @@ AudioRegionEditor::name_changed ()
 }
 
 void
-AudioRegionEditor::bounds_changed (Change what_changed)
+AudioRegionEditor::bounds_changed (PropertyChange what_changed)
 {
-	if ((what_changed & Change (PositionChanged|LengthChanged)) == Change (PositionChanged|LengthChanged)) {
+	if ((what_changed & PropertyChange (PositionChanged|LengthChanged)) == PropertyChange (PositionChanged|LengthChanged)) {
 		position_clock.set (_region->position(), true);
 		end_clock.set (_region->position() + _region->length() - 1, true);
 		length_clock.set (_region->length(), true);
-	} else if (what_changed & Change (PositionChanged)) {
+	} else if (what_changed & PropertyChange (PositionChanged)) {
 		position_clock.set (_region->position(), true);
 		end_clock.set (_region->position() + _region->length() - 1, true);
-	} else if (what_changed & Change (LengthChanged)) {
+	} else if (what_changed & PropertyChange (LengthChanged)) {
 		end_clock.set (_region->position() + _region->length() - 1, true);
 		length_clock.set (_region->length(), true);
 	}
@@ -412,6 +412,6 @@ AudioRegionEditor::sync_offset_relative_clock_changed ()
 bool
 AudioRegionEditor::on_delete_event (GdkEventAny* ev)
 {
-	bounds_changed (Change (StartChanged|LengthChanged|PositionChanged|Region::SyncOffsetChanged));
+	bounds_changed (PropertyChange (StartChanged|LengthChanged|PositionChanged|Region::SyncOffsetChanged));
 	return RegionEditor::on_delete_event (ev);
 }
diff --git a/gtk2_ardour/audio_region_editor.h b/gtk2_ardour/audio_region_editor.h
index af9d1b057b..e33caadba6 100644
--- a/gtk2_ardour/audio_region_editor.h
+++ b/gtk2_ardour/audio_region_editor.h
@@ -98,8 +98,8 @@ class AudioRegionEditor : public RegionEditor
 	PBD::ScopedConnection state_connection;
 	PBD::ScopedConnection audition_connection;
 
-	void region_changed (PBD::Change);
-	void bounds_changed (PBD::Change);
+	void region_changed (PBD::PropertyChange);
+	void bounds_changed (PBD::PropertyChange);
 	void name_changed ();
 	void gain_changed ();
 
diff --git a/gtk2_ardour/audio_region_view.cc b/gtk2_ardour/audio_region_view.cc
index 54be60bc9d..4d783956d7 100644
--- a/gtk2_ardour/audio_region_view.cc
+++ b/gtk2_ardour/audio_region_view.cc
@@ -264,7 +264,7 @@ AudioRegionView::audio_region() const
 }
 
 void
-AudioRegionView::region_changed (Change what_changed)
+AudioRegionView::region_changed (PropertyChange what_changed)
 {
 	ENSURE_GUI_THREAD (*this, &AudioRegionView::region_changed, what_changed)
 	//cerr << "AudioRegionView::region_changed() called" << endl;
@@ -372,13 +372,13 @@ AudioRegionView::region_renamed ()
 }
 
 void
-AudioRegionView::region_resized (Change what_changed)
+AudioRegionView::region_resized (PropertyChange what_changed)
 {
 	AudioGhostRegion* agr;
 
 	RegionView::region_resized(what_changed);
 
-	if (what_changed & Change (StartChanged|LengthChanged)) {
+	if (what_changed & PropertyChange (StartChanged|LengthChanged)) {
 
 		for (uint32_t n = 0; n < waves.size(); ++n) {
 			waves[n]->property_region_start() = _region->start();
diff --git a/gtk2_ardour/audio_region_view.h b/gtk2_ardour/audio_region_view.h
index 87e5d23327..767a66faed 100644
--- a/gtk2_ardour/audio_region_view.h
+++ b/gtk2_ardour/audio_region_view.h
@@ -98,7 +98,7 @@ class AudioRegionView : public RegionView
 
 	AudioRegionGainLine* get_gain_line() const { return gain_line; }
 
-	void region_changed (PBD::Change);
+	void region_changed (PBD::PropertyChange);
 	void envelope_active_changed ();
 
 	GhostRegion* add_ghost (TimeAxisView&);
@@ -150,7 +150,7 @@ class AudioRegionView : public RegionView
     void fade_in_active_changed ();
     void fade_out_active_changed ();
 
-    void region_resized (PBD::Change);
+    void region_resized (PBD::PropertyChange);
     void region_muted ();
     void region_scale_amplitude_changed ();
 	void region_renamed ();
diff --git a/gtk2_ardour/audio_streamview.cc b/gtk2_ardour/audio_streamview.cc
index 8c427f2621..6b1aed6268 100644
--- a/gtk2_ardour/audio_streamview.cc
+++ b/gtk2_ardour/audio_streamview.cc
@@ -483,8 +483,16 @@ AudioStreamView::setup_rec_box ()
 							+ _trackview.get_diskstream()->get_captured_frames(rec_regions.size()-1);
 				}
 
-				boost::shared_ptr<AudioRegion> region (boost::dynamic_pointer_cast<AudioRegion>(
-						RegionFactory::create (sources, start, 1, "", 0, Region::DefaultFlags, false)));
+				PropertyList plist; 
+				
+				plist.add (Properties::start, start);
+				plist.add (Properties::length, 1);
+				plist.add (Properties::name, string());
+				plist.add (Properties::layer, 0);
+
+				boost::shared_ptr<AudioRegion> region (
+					boost::dynamic_pointer_cast<AudioRegion>(RegionFactory::create (sources, plist, false)));
+
 				assert(region);
 				region->block_property_changes ();
 				region->set_position (_trackview.session()->transport_frame(), this);
diff --git a/gtk2_ardour/automation_region_view.cc b/gtk2_ardour/automation_region_view.cc
index f1000d7159..a796d4d7cd 100644
--- a/gtk2_ardour/automation_region_view.cc
+++ b/gtk2_ardour/automation_region_view.cc
@@ -158,7 +158,7 @@ AutomationRegionView::reset_width_dependent_items (double pixel_width)
 
 
 void
-AutomationRegionView::region_resized (PBD::Change what_changed)
+AutomationRegionView::region_resized (PBD::PropertyChange what_changed)
 {
 	RegionView::region_resized(what_changed);
 
diff --git a/gtk2_ardour/automation_region_view.h b/gtk2_ardour/automation_region_view.h
index b4f53b5921..0a1978c963 100644
--- a/gtk2_ardour/automation_region_view.h
+++ b/gtk2_ardour/automation_region_view.h
@@ -66,7 +66,7 @@ public:
 protected:
 	void create_line(boost::shared_ptr<ARDOUR::AutomationList> list);
 	bool set_position(nframes64_t pos, void* src, double* ignored);
-	void region_resized (PBD::Change what_changed);
+	void region_resized (PBD::PropertyChange what_changed);
 	bool canvas_event(GdkEvent* ev);
 	void add_automation_event (GdkEvent* event, nframes_t when, double y);
 	void entered();
diff --git a/gtk2_ardour/canvas-waveview.c b/gtk2_ardour/canvas-waveview.c
index cafc47b61f..f3a3117622 100644
--- a/gtk2_ardour/canvas-waveview.c
+++ b/gtk2_ardour/canvas-waveview.c
@@ -763,23 +763,27 @@ gnome_canvas_waveview_set_property (GObject      *object,
 		break;
 
 	case PROP_LENGTH_FUNCTION:
-		waveview->length_function = g_value_get_pointer(value);
+		waveview->length_function = (gulong (*)(void*)) g_value_get_pointer(value);
 		redraw = TRUE;
 		break;
 
 	case PROP_SOURCEFILE_LENGTH_FUNCTION:
-		waveview->sourcefile_length_function = g_value_get_pointer(value);
+		waveview->sourcefile_length_function = (gulong (*)(void*,double)) g_value_get_pointer(value);
 		redraw = TRUE;
 		break;
 
 	case PROP_PEAK_FUNCTION:
-		waveview->peak_function = g_value_get_pointer(value);
+		waveview->peak_function = 
+			(void (*)(void*,gulong,gulong,gulong,gpointer,guint32,double))
+			 g_value_get_pointer(value);
 		redraw = TRUE;
 		break;
 
 	case PROP_GAIN_FUNCTION:
-		waveview->gain_curve_function = g_value_get_pointer(value);
-		redraw = TRUE;
+		waveview->gain_curve_function = 
+			(void (*)(void *arg, double start, double end, float* vector, gint64 veclen))
+			 g_value_get_pointer(value);
+			 redraw = TRUE;
 		break;
 
 	case PROP_GAIN_SRC:
@@ -946,19 +950,19 @@ gnome_canvas_waveview_get_property (
 		break;
 
 	case PROP_LENGTH_FUNCTION:
-		g_value_set_pointer(value, waveview->length_function);
+		g_value_set_pointer(value, (void*) waveview->length_function);
 		break;
 
 	case PROP_SOURCEFILE_LENGTH_FUNCTION:
-		g_value_set_pointer(value, waveview->sourcefile_length_function);
+		g_value_set_pointer(value, (void*) waveview->sourcefile_length_function);
 		break;
 
 	case PROP_PEAK_FUNCTION:
-		g_value_set_pointer(value, waveview->peak_function);
+		g_value_set_pointer(value, (void*) waveview->peak_function);
 		break;
 
 	case PROP_GAIN_FUNCTION:
-		g_value_set_pointer(value, waveview->gain_curve_function);
+		g_value_set_pointer(value, (void*) waveview->gain_curve_function);
 		break;
 
 	case PROP_GAIN_SRC:
diff --git a/gtk2_ardour/crossfade_edit.cc b/gtk2_ardour/crossfade_edit.cc
index fd651599ea..c5d7b8d1b5 100644
--- a/gtk2_ardour/crossfade_edit.cc
+++ b/gtk2_ardour/crossfade_edit.cc
@@ -624,7 +624,7 @@ CrossfadeEditor::canvas_allocation (Gtk::Allocation& /*alloc*/)
 
 
 void
-CrossfadeEditor::xfade_changed (Change)
+CrossfadeEditor::xfade_changed (PropertyChange)
 {
 	set (xfade->fade_in(), In);
 	set (xfade->fade_out(), Out);
@@ -1220,26 +1220,42 @@ CrossfadeEditor::audition (Audition which)
 		right_length = xfade->in()->length();
 	}
 
-	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->out(), left_start_offset, left_length, "xfade out",
-													      0, Region::DefaultFlags, false)));
-	boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->in(), 0, right_length, "xfade in",
-													       0, Region::DefaultFlags, false)));
-
-	//apply a 20ms declicking fade at the start and end of auditioning
-	left->set_fade_in_active(true);
-	left->set_fade_in_length(_session->frame_rate() / 50);
-	right->set_fade_out_active(true);
-	right->set_fade_out_length(_session->frame_rate() / 50);
-
-	pl.add_region (left, 0);
-	pl.add_region (right, 1 + preroll);
+	PropertyList left_plist; 
+	PropertyList right_plist; 
+
+	
+	left_plist.add (ARDOUR::Properties::start, left_start_offset);
+	left_plist.add (ARDOUR::Properties::length, left_length);
+	left_plist.add (ARDOUR::Properties::name, string ("xfade out"));
+	left_plist.add (ARDOUR::Properties::layer, 0);
+	left_plist.add (ARDOUR::Properties::fade_in_active, true);
+	
+	right_plist.add (ARDOUR::Properties::start, 0);
+	right_plist.add (ARDOUR::Properties::length, right_length);
+	right_plist.add (ARDOUR::Properties::name, string("xfade in"));
+	right_plist.add (ARDOUR::Properties::layer, 0);
+	right_plist.add (ARDOUR::Properties::fade_out_active, true);
 
 	if (which == Left) {
-		right->set_scale_amplitude (0.0);
+		right_plist.add (ARDOUR::Properties::scale_amplitude, 0.0f);
 	} else if (which == Right) {
-		left->set_scale_amplitude (0.0);
+		left_plist.add (ARDOUR::Properties::scale_amplitude, 0.0f);
 	}
 
+	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> 
+						     (RegionFactory::create (xfade->out(), left_plist, false)));
+	boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> 
+					      (RegionFactory::create (xfade->in(), right_plist, false)));
+
+	// apply a 20ms declicking fade at the start and end of auditioning
+	// XXX this should really be a property
+
+	left->set_fade_in_length (_session->frame_rate() / 50);
+	right->set_fade_out_length (_session->frame_rate() / 50);
+
+	pl.add_region (left, 0);
+	pl.add_region (right, 1 + preroll);
+
 	/* there is only one ... */
 	pl.foreach_crossfade (sigc::mem_fun (*this, &CrossfadeEditor::setup));
 
@@ -1255,8 +1271,15 @@ CrossfadeEditor::audition_both ()
 void
 CrossfadeEditor::audition_left_dry ()
 {
-	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->out(), xfade->out()->length() - xfade->length(), xfade->length(), "xfade left",
-													      0, Region::DefaultFlags, false)));
+	PropertyList plist; 
+
+	plist.add (ARDOUR::Properties::start, xfade->out()->length() - xfade->length());
+	plist.add (ARDOUR::Properties::length, xfade->length());
+	plist.add (ARDOUR::Properties::name, string("xfade left"));
+	plist.add (ARDOUR::Properties::layer, 0);
+	
+	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> 
+					     (RegionFactory::create (xfade->out(), plist, false)));
 
 	_session->audition_region (left);
 }
@@ -1270,8 +1293,16 @@ CrossfadeEditor::audition_left ()
 void
 CrossfadeEditor::audition_right_dry ()
 {
-	boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->in(), 0, xfade->length(), "xfade in",
-													       0, Region::DefaultFlags, false)));
+	PropertyList plist; 
+
+	plist.add (ARDOUR::Properties::start, 0);
+	plist.add (ARDOUR::Properties::length, xfade->length());
+	plist.add (ARDOUR::Properties::name, string ("xfade right"));
+	plist.add (ARDOUR::Properties::layer, 0);
+
+	boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> 
+					      (RegionFactory::create (xfade->in(), plist, false)));
+
 	_session->audition_region (right);
 }
 
diff --git a/gtk2_ardour/crossfade_edit.h b/gtk2_ardour/crossfade_edit.h
index d92288e650..a05bb093f0 100644
--- a/gtk2_ardour/crossfade_edit.h
+++ b/gtk2_ardour/crossfade_edit.h
@@ -213,7 +213,7 @@ class CrossfadeEditor : public ArdourDialog
 	void audition_right_dry ();
 	void audition_right ();
 
-	void xfade_changed (PBD::Change);
+	void xfade_changed (PBD::PropertyChange);
 
 	void dump ();
 };
diff --git a/gtk2_ardour/crossfade_view.cc b/gtk2_ardour/crossfade_view.cc
index 514daa4f3e..ca333e67a6 100644
--- a/gtk2_ardour/crossfade_view.cc
+++ b/gtk2_ardour/crossfade_view.cc
@@ -82,7 +82,7 @@ CrossfadeView::CrossfadeView (ArdourCanvas::Group *parent,
 
 	group->signal_event().connect (sigc::bind (sigc::mem_fun (tv.editor(), &PublicEditor::canvas_crossfade_view_event), group, this));
 
-	crossfade_changed (Change (~0));
+	crossfade_changed (PropertyChange (~0));
 
 	crossfade->StateChanged.connect (*this, ui_bind (&CrossfadeView::crossfade_changed, this, _1), gui_context());
 	ColorsChanged.connect (sigc::mem_fun (*this, &CrossfadeView::color_handler));
@@ -123,7 +123,7 @@ CrossfadeView::set_height (double height)
 }
 
 void
-CrossfadeView::crossfade_changed (Change what_changed)
+CrossfadeView::crossfade_changed (PropertyChange what_changed)
 {
 	bool need_redraw_curves = false;
 
diff --git a/gtk2_ardour/crossfade_view.h b/gtk2_ardour/crossfade_view.h
index e141a30cb1..3e550e4788 100644
--- a/gtk2_ardour/crossfade_view.h
+++ b/gtk2_ardour/crossfade_view.h
@@ -75,7 +75,7 @@ struct CrossfadeView : public TimeAxisViewItem
     ArdourCanvas::Line *fade_out;
     ArdourCanvas::Item *active_button;
 
-    void crossfade_changed (PBD::Change);
+    void crossfade_changed (PBD::PropertyChange);
     void active_changed ();
 	void redraw_curves ();
 	void color_handler ();
diff --git a/gtk2_ardour/editor.cc b/gtk2_ardour/editor.cc
index 4f44164d37..075a9399f3 100644
--- a/gtk2_ardour/editor.cc
+++ b/gtk2_ardour/editor.cc
@@ -1133,7 +1133,7 @@ Editor::set_session (Session *t)
 	handle_new_duration ();
 
 	restore_ruler_visibility ();
-	//tempo_map_changed (Change (0));
+	//tempo_map_changed (PropertyChange (0));
 	_session->tempo_map().apply_with_metrics (*this, &Editor::draw_metric_marks);
 
 	for (TrackViewList::iterator i = track_views.begin(); i != track_views.end(); ++i) {
@@ -3737,7 +3737,7 @@ Editor::edit_xfade (boost::weak_ptr<Crossfade> wxfade)
 	}
 
 	cew.apply ();
-	xfade->StateChanged (Change (~0));
+	xfade->StateChanged (PropertyChange (~0));
 }
 
 PlaylistSelector&
@@ -3993,7 +3993,7 @@ Editor::new_playlists (TimeAxisView* v)
 	begin_reversible_command (_("new playlists"));
 	vector<boost::shared_ptr<ARDOUR::Playlist> > playlists;
 	_session->playlists->get (playlists);
-	mapover_tracks (sigc::bind (sigc::mem_fun (*this, &Editor::mapped_use_new_playlist), playlists), v, RouteGroup::Edit);
+	mapover_tracks (sigc::bind (sigc::mem_fun (*this, &Editor::mapped_use_new_playlist), playlists), v, ARDOUR::Properties::edit.id);
 	commit_reversible_command ();
 }
 
@@ -4009,7 +4009,7 @@ Editor::copy_playlists (TimeAxisView* v)
 	begin_reversible_command (_("copy playlists"));
 	vector<boost::shared_ptr<ARDOUR::Playlist> > playlists;
 	_session->playlists->get (playlists);
-	mapover_tracks (sigc::bind (sigc::mem_fun (*this, &Editor::mapped_use_copy_playlist), playlists), v, RouteGroup::Edit);
+	mapover_tracks (sigc::bind (sigc::mem_fun (*this, &Editor::mapped_use_copy_playlist), playlists), v, ARDOUR::Properties::edit.id);
 	commit_reversible_command ();
 }
 
@@ -4024,7 +4024,7 @@ Editor::clear_playlists (TimeAxisView* v)
 	begin_reversible_command (_("clear playlists"));
 	vector<boost::shared_ptr<ARDOUR::Playlist> > playlists;
 	_session->playlists->get (playlists);
-	mapover_tracks (sigc::mem_fun (*this, &Editor::mapped_clear_playlist), v, RouteGroup::Edit);
+	mapover_tracks (sigc::mem_fun (*this, &Editor::mapped_clear_playlist), v, ARDOUR::Properties::edit.id);
 	commit_reversible_command ();
 }
 
@@ -4562,7 +4562,7 @@ Editor::get_regions_for_action (RegionSelection& rs, bool allow_entered, bool al
 		for (RegionSelection::iterator i = rs.begin (); i != rs.end(); ++i) {
 
 		 	RouteGroup* g = (*i)->get_time_axis_view().route_group ();
-		 	if (g && g->active_property (RouteGroup::Edit)) {
+		 	if (g && g->is_active() && g->is_edit()) {
 		 		tracks.add (axis_views_from_routes (g->route_list()));
 		 	}
 			
diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index 49742c6f45..6b79f7d3a6 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -520,7 +520,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	void location_changed (ARDOUR::Location *);
 	void location_flags_changed (ARDOUR::Location *, void *);
 	void refresh_location_display ();
-	void refresh_location_display_s (PBD::Change);
+	void refresh_location_display_s (PBD::PropertyChange);
 	void refresh_location_display_internal (ARDOUR::Locations::LocationList&);
 	void add_new_location (ARDOUR::Location *);
 	void location_gone (ARDOUR::Location *);
@@ -578,9 +578,9 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 
 	void sort_track_selection (TrackViewList* sel = 0);
 
-	void get_equivalent_regions (RegionView* rv, std::vector<RegionView*> &, ARDOUR::RouteGroup::Property) const;
-	RegionSelection get_equivalent_regions (RegionSelection &, ARDOUR::RouteGroup::Property) const;
-	void mapover_tracks (sigc::slot<void,RouteTimeAxisView&,uint32_t> sl, TimeAxisView*, ARDOUR::RouteGroup::Property) const;
+	void get_equivalent_regions (RegionView* rv, std::vector<RegionView*> &, PBD::PropertyID) const;
+	RegionSelection get_equivalent_regions (RegionSelection &, PBD::PropertyID) const;
+	void mapover_tracks (sigc::slot<void,RouteTimeAxisView&,uint32_t> sl, TimeAxisView*, PBD::PropertyID) const;
 
 	/* functions to be passed to mapover_tracks(), possibly with sigc::bind()-supplied arguments */
 
@@ -1475,7 +1475,7 @@ public:
 	void draw_metric_marks (const ARDOUR::Metrics& metrics);
 
 	void compute_current_bbt_points (nframes_t left, nframes_t right);
-	void tempo_map_changed (PBD::Change);
+	void tempo_map_changed (PBD::PropertyChange);
 	void redisplay_tempo (bool immediate_redraw);
 
 	void snap_to (nframes64_t& first, int32_t direction = 0, bool for_mark = false);
diff --git a/gtk2_ardour/editor_actions.cc b/gtk2_ardour/editor_actions.cc
index b46b44b3eb..d137ed6351 100644
--- a/gtk2_ardour/editor_actions.cc
+++ b/gtk2_ardour/editor_actions.cc
@@ -673,8 +673,8 @@ Editor::register_actions ()
 	ActionManager::register_radio_action (editor_actions, edit_point_group, X_("edit-at-mouse"), _("Mouse"), (sigc::bind (sigc::mem_fun(*this, &Editor::edit_point_chosen), Editing::EditAtPlayhead)));
 	ActionManager::register_radio_action (editor_actions, edit_point_group, X_("edit-at-selected-marker"), _("Marker"), (sigc::bind (sigc::mem_fun(*this, &Editor::edit_point_chosen), Editing::EditAtPlayhead)));
 
-	ActionManager::register_action (editor_actions, "cycle-edit-point", _("Change Edit Point"), sigc::bind (sigc::mem_fun (*this, &Editor::cycle_edit_point), false));
-	ActionManager::register_action (editor_actions, "cycle-edit-point-with-marker", _("Change Edit Point Including Marker"), sigc::bind (sigc::mem_fun (*this, &Editor::cycle_edit_point), true));
+	ActionManager::register_action (editor_actions, "cycle-edit-point", _("PropertyChange Edit Point"), sigc::bind (sigc::mem_fun (*this, &Editor::cycle_edit_point), false));
+	ActionManager::register_action (editor_actions, "cycle-edit-point-with-marker", _("PropertyChange Edit Point Including Marker"), sigc::bind (sigc::mem_fun (*this, &Editor::cycle_edit_point), true));
 	if (!Profile->get_sae()) {
 		ActionManager::register_action (editor_actions, "set-edit-splice", _("Splice"), sigc::bind (sigc::mem_fun (*this, &Editor::set_edit_mode), Splice));
 	}
diff --git a/gtk2_ardour/editor_audio_import.cc b/gtk2_ardour/editor_audio_import.cc
index de275f8738..c70832182a 100644
--- a/gtk2_ardour/editor_audio_import.cc
+++ b/gtk2_ardour/editor_audio_import.cc
@@ -720,8 +720,16 @@ Editor::add_sources (vector<Glib::ustring> paths, SourceList& sources, nframes64
 
 		region_name = region_name_from_path (paths.front(), (sources.size() > 1), false);
 
-		boost::shared_ptr<Region> r = RegionFactory::create (sources, 0, sources[0]->length(pos), region_name, 0,
-								     Region::Flag (Region::DefaultFlags|Region::WholeFile|Region::External));
+		PropertyList plist; 
+		
+		plist.add (ARDOUR::Properties::start, 0);
+		plist.add (ARDOUR::Properties::length, sources[0]->length (pos));
+		plist.add (ARDOUR::Properties::name, region_name);
+		plist.add (ARDOUR::Properties::layer, 0);
+		plist.add (ARDOUR::Properties::whole_file, true);
+		plist.add (ARDOUR::Properties::external, true);
+
+		boost::shared_ptr<Region> r = RegionFactory::create (sources, plist);
 
 		if (use_timestamp && boost::dynamic_pointer_cast<AudioRegion>(r)) {
 			boost::dynamic_pointer_cast<AudioRegion>(r)->special_set_position(sources[0]->natural_position());
@@ -745,8 +753,16 @@ Editor::add_sources (vector<Glib::ustring> paths, SourceList& sources, nframes64
 
 			region_name = region_name_from_path ((*x)->path(), false, false, sources.size(), n);
 
-			boost::shared_ptr<Region> r = RegionFactory::create (just_one, 0, (*x)->length(pos), region_name, 0,
-									     Region::Flag (Region::DefaultFlags|Region::WholeFile|Region::External));
+			PropertyList plist; 
+			
+			plist.add (ARDOUR::Properties::start, 0);
+			plist.add (ARDOUR::Properties::length, (*x)->length (pos));
+			plist.add (ARDOUR::Properties::name, region_name);
+			plist.add (ARDOUR::Properties::layer, 0);
+			plist.add (ARDOUR::Properties::whole_file, true);
+			plist.add (ARDOUR::Properties::external, true);
+
+			boost::shared_ptr<Region> r = RegionFactory::create (just_one, plist);
 
 			if (use_timestamp && boost::dynamic_pointer_cast<AudioRegion>(r)) {
 				boost::dynamic_pointer_cast<AudioRegion>(r)->special_set_position((*x)->natural_position());
diff --git a/gtk2_ardour/editor_markers.cc b/gtk2_ardour/editor_markers.cc
index d23afbf14c..33e0962596 100644
--- a/gtk2_ardour/editor_markers.cc
+++ b/gtk2_ardour/editor_markers.cc
@@ -339,7 +339,7 @@ Editor::refresh_location_display ()
 }
 
 void
-Editor::refresh_location_display_s (Change)
+Editor::refresh_location_display_s (PropertyChange)
 {
 	ENSURE_GUI_THREAD (*this, &Editor::refresh_location_display_s, ignored)
 
diff --git a/gtk2_ardour/editor_mouse.cc b/gtk2_ardour/editor_mouse.cc
index 3119729bab..fa641dd9b8 100644
--- a/gtk2_ardour/editor_mouse.cc
+++ b/gtk2_ardour/editor_mouse.cc
@@ -687,14 +687,14 @@ Editor::button_press_handler_1 (ArdourCanvas::Item* item, GdkEvent* event, ItemT
 			switch (item_type) {
 			case FadeInHandleItem:
 			{
-				RegionSelection s = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+				RegionSelection s = get_equivalent_regions (selection->regions, Properties::edit.id);
 				_drags->set (new FadeInDrag (this, item, reinterpret_cast<RegionView*> (item->get_data("regionview")), s), event);
 				return true;
 			}
 
 			case FadeOutHandleItem:
 			{
-				RegionSelection s = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+				RegionSelection s = get_equivalent_regions (selection->regions, Properties::edit.id);
 				_drags->set (new FadeOutDrag (this, item, reinterpret_cast<RegionView*> (item->get_data("regionview")), s), event);
 				return true;
 			}
@@ -717,7 +717,7 @@ Editor::button_press_handler_1 (ArdourCanvas::Item* item, GdkEvent* event, ItemT
 
 			case RegionViewNameHighlight:
 			{
-				RegionSelection s = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+				RegionSelection s = get_equivalent_regions (selection->regions, Properties::edit.id);
 				_drags->set (new TrimDrag (this, item, clicked_regionview, s.by_layer()), event);
 				return true;
 				break;
@@ -726,7 +726,7 @@ Editor::button_press_handler_1 (ArdourCanvas::Item* item, GdkEvent* event, ItemT
 			case RegionViewName:
 			{
 				/* rename happens on edit clicks */
-				RegionSelection s = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+				RegionSelection s = get_equivalent_regions (selection->regions, Properties::edit.id);
 				_drags->set (new TrimDrag (this, clicked_regionview->get_name_highlight(), clicked_regionview, s.by_layer()), event);
 				return true;
 				break;
@@ -2206,7 +2206,7 @@ Editor::single_start_trim (RegionView& rv, nframes64_t frame_delta, bool left_di
 		}
 	}
 
-	rv.region_changed (Change (LengthChanged|PositionChanged|StartChanged));
+	rv.region_changed (PropertyChange (LengthChanged|PositionChanged|StartChanged));
 }
 
 void
@@ -2260,7 +2260,7 @@ Editor::single_end_trim (RegionView& rv, nframes64_t frame_delta, bool left_dire
 			region_right->trim_front(region->last_frame() + 1, this);
 		}
 
-		rv.region_changed (Change (LengthChanged|PositionChanged|StartChanged));
+		rv.region_changed (PropertyChange (LengthChanged|PositionChanged|StartChanged));
 	}
 	else {
 		rv.region_changed (LengthChanged);
@@ -2484,7 +2484,7 @@ Editor::add_region_drag (ArdourCanvas::Item* item, GdkEvent* event, RegionView*
 	if (Config->get_edit_mode() == Splice) {
 		_drags->add (new RegionSpliceDrag (this, item, region_view, selection->regions.by_layer()));
 	} else {
-		RegionSelection s = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+		RegionSelection s = get_equivalent_regions (selection->regions, ARDOUR::Properties::edit.id);
 		_drags->add (new RegionMoveDrag (this, item, region_view, s.by_layer(), false, false));
 	}
 
@@ -2499,7 +2499,7 @@ Editor::add_region_copy_drag (ArdourCanvas::Item* item, GdkEvent* event, RegionV
 
 	_region_motion_group->raise_to_top ();
 
-	RegionSelection s = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+	RegionSelection s = get_equivalent_regions (selection->regions, ARDOUR::Properties::edit.id);
 	_drags->add (new RegionMoveDrag (this, item, region_view, s.by_layer(), false, true));
 }
 
@@ -2512,7 +2512,7 @@ Editor::add_region_brush_drag (ArdourCanvas::Item* item, GdkEvent* event, Region
 		return;
 	}
 
-	RegionSelection s = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+	RegionSelection s = get_equivalent_regions (selection->regions, ARDOUR::Properties::edit.id);
 	_drags->add (new RegionMoveDrag (this, item, region_view, s.by_layer(), true, false));
 
 	begin_reversible_command (_("Drag region brush"));
diff --git a/gtk2_ardour/editor_ops.cc b/gtk2_ardour/editor_ops.cc
index 16773f269d..a1000b7077 100644
--- a/gtk2_ardour/editor_ops.cc
+++ b/gtk2_ardour/editor_ops.cc
@@ -2668,8 +2668,15 @@ Editor::region_from_selection ()
 
 		internal_start = start - current->position();
 		_session->region_name (new_name, current->name(), true);
-		boost::shared_ptr<Region> region (RegionFactory::create (current,
-				internal_start, selection_cnt, new_name));
+
+		PropertyList plist; 
+		
+		plist.add (ARDOUR::Properties::start, internal_start);
+		plist.add (ARDOUR::Properties::length, selection_cnt);
+		plist.add (ARDOUR::Properties::name, new_name);
+		plist.add (ARDOUR::Properties::layer, 0);
+
+		boost::shared_ptr<Region> region (RegionFactory::create (current, plist));
 	}
 }
 
@@ -2702,8 +2709,13 @@ Editor::create_region_from_selection (vector<boost::shared_ptr<Region> >& new_re
 		internal_start = start - current->position();
 		_session->region_name (new_name, current->name(), true);
 
-		new_regions.push_back (RegionFactory::create (current,
-					internal_start, end - start + 1, new_name));
+		PropertyList plist; 
+		
+		plist.add (ARDOUR::Properties::start, internal_start);
+		plist.add (ARDOUR::Properties::length, end - start + 1);
+		plist.add (ARDOUR::Properties::name, new_name);
+
+		new_regions.push_back (RegionFactory::create (current, plist));
 	}
 }
 
@@ -3604,7 +3616,7 @@ Editor::trim_to_region(bool forward)
 		    }
 
 		    region->trim_end((nframes64_t) (next_region->first_frame() * speed), this);
-		    arv->region_changed (Change (LengthChanged));
+		    arv->region_changed (PropertyChange (LengthChanged));
 		}
 		else {
 
@@ -3615,7 +3627,7 @@ Editor::trim_to_region(bool forward)
 		    }
 
 		    region->trim_front((nframes64_t) ((next_region->last_frame() + 1) * speed), this);
-		    arv->region_changed (Change (LengthChanged|PositionChanged|StartChanged));
+		    arv->region_changed (PropertyChange (LengthChanged|PositionChanged|StartChanged));
 		}
 
 		XMLNode &after = playlist->get_state();
@@ -4870,7 +4882,7 @@ Editor::brush (nframes64_t pos)
 void
 Editor::reset_region_gain_envelopes ()
 {
-	RegionSelection rs = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+	RegionSelection rs = get_equivalent_regions (selection->regions, ARDOUR::Properties::edit.id);
 
 	if (!_session || rs.empty()) {
 		return;
@@ -4895,7 +4907,7 @@ Editor::reset_region_gain_envelopes ()
 void
 Editor::toggle_gain_envelope_visibility ()
 {
-	RegionSelection rs = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+	RegionSelection rs = get_equivalent_regions (selection->regions, ARDOUR::Properties::edit.id);
 
 	if (!_session || rs.empty()) {
 		return;
@@ -4919,7 +4931,7 @@ Editor::toggle_gain_envelope_visibility ()
 void
 Editor::toggle_gain_envelope_active ()
 {
-	RegionSelection rs = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+	RegionSelection rs = get_equivalent_regions (selection->regions, ARDOUR::Properties::edit.id);
 
 	if (!_session || rs.empty()) {
 		return;
@@ -4942,7 +4954,7 @@ Editor::toggle_gain_envelope_active ()
 void
 Editor::toggle_region_lock ()
 {
-	RegionSelection rs = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+	RegionSelection rs = get_equivalent_regions (selection->regions, ARDOUR::Properties::edit.id);
 
 	if (!_session || rs.empty()) {
 		return;
@@ -4962,7 +4974,7 @@ Editor::toggle_region_lock ()
 void
 Editor::set_region_lock_style (Region::PositionLockStyle ps)
 {
-	RegionSelection rs = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+	RegionSelection rs = get_equivalent_regions (selection->regions, ARDOUR::Properties::edit.id);
 
 	if (!_session || rs.empty()) {
 		return;
@@ -4984,7 +4996,7 @@ Editor::set_region_lock_style (Region::PositionLockStyle ps)
 void
 Editor::toggle_region_mute ()
 {
-	RegionSelection rs = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+	RegionSelection rs = get_equivalent_regions (selection->regions, ARDOUR::Properties::edit.id);
 
 	if (!_session || rs.empty()) {
 		return;
@@ -5004,7 +5016,7 @@ Editor::toggle_region_mute ()
 void
 Editor::toggle_region_opaque ()
 {
-	RegionSelection rs = get_equivalent_regions (selection->regions, RouteGroup::Edit);
+	RegionSelection rs = get_equivalent_regions (selection->regions, ARDOUR::Properties::edit.id);
 
 	if (!_session || rs.empty()) {
 		return;
@@ -5959,7 +5971,14 @@ Editor::split_region_at_points (boost::shared_ptr<Region> r, AnalysisFeatureList
 
 		/* do NOT announce new regions 1 by one, just wait till they are all done */
 
-		boost::shared_ptr<Region> nr = RegionFactory::create (r->sources(), file_start, len, new_name, 0, Region::DefaultFlags, false);
+		PropertyList plist; 
+		
+		plist.add (ARDOUR::Properties::start, file_start);
+		plist.add (ARDOUR::Properties::length, len);
+		plist.add (ARDOUR::Properties::name, new_name);
+		plist.add (ARDOUR::Properties::layer, 0);
+
+		boost::shared_ptr<Region> nr = RegionFactory::create (r->sources(), plist, false);
 		pl->add_region (nr, pos);
 
 		pos += len;
@@ -5972,7 +5991,14 @@ Editor::split_region_at_points (boost::shared_ptr<Region> r, AnalysisFeatureList
 			file_start = r->start() + (pos - r->position());
 			len = r->last_frame() - pos;
 
-			nr = RegionFactory::create (r->sources(), file_start, len, new_name, 0, Region::DefaultFlags);
+			PropertyList plist2; 
+			
+			plist2.add (ARDOUR::Properties::start, file_start);
+			plist2.add (ARDOUR::Properties::length, len);
+			plist2.add (ARDOUR::Properties::name, new_name);
+			plist2.add (ARDOUR::Properties::layer, 0);
+
+			nr = RegionFactory::create (r->sources(), plist2); 
 			pl->add_region (nr, pos);
 
 			break;
diff --git a/gtk2_ardour/editor_regions.cc b/gtk2_ardour/editor_regions.cc
index 58a0a5d7e7..b3ca136bcf 100644
--- a/gtk2_ardour/editor_regions.cc
+++ b/gtk2_ardour/editor_regions.cc
@@ -347,7 +347,7 @@ EditorRegions::add_region (boost::shared_ptr<Region> region)
 
 
 void
-EditorRegions::region_changed (Change what_changed, boost::weak_ptr<Region> region)
+EditorRegions::region_changed (PropertyChange what_changed, boost::weak_ptr<Region> region)
 {
 	ENSURE_GUI_THREAD (*this, &EditorRegions::region_changed, what_changed, region)
 
diff --git a/gtk2_ardour/editor_regions.h b/gtk2_ardour/editor_regions.h
index 5a31eb2fd2..92adb72621 100644
--- a/gtk2_ardour/editor_regions.h
+++ b/gtk2_ardour/editor_regions.h
@@ -104,7 +104,7 @@ private:
 
 	Columns _columns;
 
-	void region_changed (PBD::Change, boost::weak_ptr<ARDOUR::Region>);
+	void region_changed (PBD::PropertyChange, boost::weak_ptr<ARDOUR::Region>);
 	void selection_changed ();
 	sigc::connection _change_connection;
 	bool set_selected_in_subrow (boost::shared_ptr<ARDOUR::Region>, Gtk::TreeModel::Row const &, int);
diff --git a/gtk2_ardour/editor_route_groups.cc b/gtk2_ardour/editor_route_groups.cc
index 9cd845ca08..c6ee08fae6 100644
--- a/gtk2_ardour/editor_route_groups.cc
+++ b/gtk2_ardour/editor_route_groups.cc
@@ -234,12 +234,16 @@ EditorRouteGroups::set_activation (RouteGroup* g, bool a)
 ARDOUR::RouteGroup *
 EditorRouteGroups::new_route_group () const
 {
-	RouteGroup* g = new RouteGroup (
-		*_session,
-		"",
-		RouteGroup::Active,
-		(RouteGroup::Property) (RouteGroup::Mute | RouteGroup::Solo | RouteGroup::Edit)
-		);
+	PropertyList plist;
+
+	plist.add (Properties::active, true);
+	plist.add (Properties::mute, true);
+	plist.add (Properties::solo, true);
+	plist.add (Properties::edit, true);
+
+	RouteGroup* g = new RouteGroup (*_session, "");
+
+	g->set_properties (plist);
 
 	RouteGroupDialog d (g, Gtk::Stock::NEW);
 	int const r = d.do_run ();
@@ -255,12 +259,16 @@ EditorRouteGroups::new_route_group () const
 void
 EditorRouteGroups::run_new_group_dialog (const RouteList& rl)
 {
-	RouteGroup* g = new RouteGroup (
-		*_session,
-		"",
-		RouteGroup::Active,
-		(RouteGroup::Property) (RouteGroup::Mute | RouteGroup::Solo | RouteGroup::Edit | RouteGroup::RecEnable)
-		);
+	PropertyList plist;
+
+	plist.add (Properties::active, true);
+	plist.add (Properties::mute, true);
+	plist.add (Properties::solo, true);
+	plist.add (Properties::recenable, true);
+	plist.add (Properties::edit, true);
+
+	RouteGroup* g = new RouteGroup (*_session, "");
+	g->set_properties (plist);
 
 	RouteGroupDialog d (g, Gtk::Stock::NEW);
 	int const r = d.do_run ();
@@ -533,18 +541,22 @@ EditorRouteGroups::row_change (const Gtk::TreeModel::Path&, const Gtk::TreeModel
 		}
 	}
 
-	group->set_property (RouteGroup::Gain, (*iter)[_columns.gain]);
-	group->set_property (RouteGroup::RecEnable, (*iter)[_columns.record]);
-	group->set_property (RouteGroup::Mute, (*iter)[_columns.mute]);
-	group->set_property (RouteGroup::Solo, (*iter)[_columns.solo]);
-	group->set_property (RouteGroup::Select, (*iter)[_columns.select]);
-	group->set_property (RouteGroup::Edit, (*iter)[_columns.edits]);
-
-	string name = (*iter)[_columns.text];
-
-	if (name != group->name()) {
-		group->set_name (name);
-	}
+	PropertyList plist;
+	bool val = (*iter)[_columns.gain];
+	plist.add (Properties::gain, val);
+	val = (*iter)[_columns.record];
+	plist.add (Properties::recenable, val);
+	val = (*iter)[_columns.mute];
+	plist.add (Properties::mute, val);
+	val = (*iter)[_columns.solo];
+	plist.add (Properties::solo, val);
+	val = (*iter)[_columns.select];
+	plist.add (Properties::select, val);
+	val = (*iter)[_columns.edits];
+	plist.add (Properties::edit, val);
+	plist.add (Properties::name, string ((*iter)[_columns.text]));
+	
+	group->set_properties (plist);
 }
 
 void
@@ -556,12 +568,12 @@ EditorRouteGroups::add (RouteGroup* group)
 	TreeModel::Row row = *(_model->append());
 
 	row[_columns.is_visible] = !group->is_hidden();
-	row[_columns.gain] = group->property(RouteGroup::Gain);
-	row[_columns.record] = group->property(RouteGroup::RecEnable);
-	row[_columns.mute] = group->property(RouteGroup::Mute);
-	row[_columns.solo] = group->property(RouteGroup::Solo);
-	row[_columns.select] = group->property(RouteGroup::Select);
-	row[_columns.edits] = group->property(RouteGroup::Edit);
+	row[_columns.gain] = group->is_gain ();
+	row[_columns.record] = group->is_recenable();
+	row[_columns.mute] = group->is_mute ();
+	row[_columns.solo] = group->is_solo ();
+	row[_columns.select] = group->is_select ();
+	row[_columns.edits] = group->is_edit ();
 
 	_in_row_change = true;
 
@@ -622,12 +634,12 @@ EditorRouteGroups::flags_changed (void*, RouteGroup* group)
 		if (group == (*iter)[_columns.routegroup]) {
 			(*iter)[_columns.is_visible] = !group->is_hidden();
 			(*iter)[_columns.text] = group->name();
-			(*iter)[_columns.gain] = group->property(RouteGroup::Gain);
-			(*iter)[_columns.record] = group->property(RouteGroup::RecEnable);
-			(*iter)[_columns.mute] = group->property(RouteGroup::Mute);
-			(*iter)[_columns.solo] = group->property(RouteGroup::Solo);
-			(*iter)[_columns.select] = group->property(RouteGroup::Select);
-			(*iter)[_columns.edits] = group->property(RouteGroup::Edit);
+			(*iter)[_columns.gain] = group->is_gain ();
+			(*iter)[_columns.record] = group->is_recenable ();
+			(*iter)[_columns.mute] = group->is_mute ();
+			(*iter)[_columns.solo] = group->is_solo ();
+			(*iter)[_columns.select] = group->is_select ();
+			(*iter)[_columns.edits] = group->is_edit ();
 		}
 	}
 
diff --git a/gtk2_ardour/editor_selection.cc b/gtk2_ardour/editor_selection.cc
index 2b94a05619..3e5b412c85 100644
--- a/gtk2_ardour/editor_selection.cc
+++ b/gtk2_ardour/editor_selection.cc
@@ -292,7 +292,7 @@ Editor::get_onscreen_tracks (TrackViewList& tvl)
  */
 
 void
-Editor::mapover_tracks (sigc::slot<void, RouteTimeAxisView&, uint32_t> sl, TimeAxisView* basis, RouteGroup::Property prop) const
+Editor::mapover_tracks (sigc::slot<void, RouteTimeAxisView&, uint32_t> sl, TimeAxisView* basis, PBD::PropertyID prop) const
 {
 	RouteTimeAxisView* route_basis = dynamic_cast<RouteTimeAxisView*> (basis);
 	if (route_basis == 0) {
@@ -303,7 +303,7 @@ Editor::mapover_tracks (sigc::slot<void, RouteTimeAxisView&, uint32_t> sl, TimeA
 	tracks.insert (route_basis);
 
 	RouteGroup* group = route_basis->route()->route_group();
-	if (group && group->active_property (prop)) {
+	if (group && group->enabled_property (prop)) {
 
 		/* the basis is a member of an active route group, with the appropriate
 		   properties; find other members */
@@ -353,9 +353,9 @@ Editor::mapped_get_equivalent_regions (RouteTimeAxisView& tv, uint32_t, RegionVi
 }
 
 void
-Editor::get_equivalent_regions (RegionView* basis, vector<RegionView*>& equivalent_regions, RouteGroup::Property prop) const
+Editor::get_equivalent_regions (RegionView* basis, vector<RegionView*>& equivalent_regions, PBD::PropertyID property) const
 {
-	mapover_tracks (sigc::bind (sigc::mem_fun (*this, &Editor::mapped_get_equivalent_regions), basis, &equivalent_regions), &basis->get_trackview(), prop);
+	mapover_tracks (sigc::bind (sigc::mem_fun (*this, &Editor::mapped_get_equivalent_regions), basis, &equivalent_regions), &basis->get_trackview(), property);
 
 	/* add clicked regionview since we skipped all other regions in the same track as the one it was in */
 
@@ -363,7 +363,7 @@ Editor::get_equivalent_regions (RegionView* basis, vector<RegionView*>& equivale
 }
 
 RegionSelection
-Editor::get_equivalent_regions (RegionSelection & basis, RouteGroup::Property prop) const
+Editor::get_equivalent_regions (RegionSelection & basis, PBD::PropertyID prop) const
 {
 	RegionSelection equivalent;
 
@@ -476,7 +476,7 @@ Editor::set_selected_regionview_from_click (bool press, Selection::Operation op,
 				if (press) {
 
 					if (selection->selected (clicked_routeview)) {
-						get_equivalent_regions (clicked_regionview, all_equivalent_regions, RouteGroup::Select);
+						get_equivalent_regions (clicked_regionview, all_equivalent_regions, ARDOUR::Properties::select.id);
 					} else {
 						all_equivalent_regions.push_back (clicked_regionview);
 					}
@@ -494,7 +494,7 @@ Editor::set_selected_regionview_from_click (bool press, Selection::Operation op,
 
 		case Selection::Set:
 			if (!selection->selected (clicked_regionview)) {
-				get_equivalent_regions (clicked_regionview, all_equivalent_regions, RouteGroup::Select);
+				get_equivalent_regions (clicked_regionview, all_equivalent_regions, ARDOUR::Properties::select.id);
 				selection->set (all_equivalent_regions);
 				commit = true;
 			} else {
diff --git a/gtk2_ardour/editor_tempodisplay.cc b/gtk2_ardour/editor_tempodisplay.cc
index 9995c50a71..1c3f018095 100644
--- a/gtk2_ardour/editor_tempodisplay.cc
+++ b/gtk2_ardour/editor_tempodisplay.cc
@@ -93,7 +93,7 @@ Editor::draw_metric_marks (const Metrics& metrics)
 }
 
 void
-Editor::tempo_map_changed (Change ignored)
+Editor::tempo_map_changed (PropertyChange ignored)
 {
 	if (!_session) {
 		return;
diff --git a/gtk2_ardour/lineset.h b/gtk2_ardour/lineset.h
index e4f836717f..66b4806439 100644
--- a/gtk2_ardour/lineset.h
+++ b/gtk2_ardour/lineset.h
@@ -65,7 +65,7 @@ public:
 	 */
 	void change_line_width(double coord, double width);
 
-	/** Change the color of a line.
+	/** PropertyChange the color of a line.
 	 */
 	void change_line_color(double coord, uint32_t color);
 
diff --git a/gtk2_ardour/midi_region_view.cc b/gtk2_ardour/midi_region_view.cc
index 681be7520e..576abafc1b 100644
--- a/gtk2_ardour/midi_region_view.cc
+++ b/gtk2_ardour/midi_region_view.cc
@@ -963,7 +963,7 @@ MidiRegionView::~MidiRegionView ()
 }
 
 void
-MidiRegionView::region_resized (Change what_changed)
+MidiRegionView::region_resized (PropertyChange what_changed)
 {
 	RegionView::region_resized(what_changed);
 
diff --git a/gtk2_ardour/midi_region_view.h b/gtk2_ardour/midi_region_view.h
index bc34416a03..a08ef7c98d 100644
--- a/gtk2_ardour/midi_region_view.h
+++ b/gtk2_ardour/midi_region_view.h
@@ -136,7 +136,7 @@ class MidiRegionView : public RegionView
 	 */
 	void get_patch_key_at(double time, uint8_t channel, MIDI::Name::PatchPrimaryKey& key);
 
-	/** Change the 'automation' data of old_program to new values which correspond to new_patch.
+	/** PropertyChange the 'automation' data of old_program to new values which correspond to new_patch.
 	 * @param old_program the program change event which is to be altered
 	 * @param new_patch the new lsb, msb and program number which are to be set
 	 */
@@ -239,7 +239,7 @@ class MidiRegionView : public RegionView
 	 */
 	void change_velocity(ArdourCanvas::CanvasNoteEvent* ev, int8_t velocity, bool relative=false);
 
-	/** Change the channel of the selection.
+	/** PropertyChange the channel of the selection.
 	 * @param channel - the channel number of the new channel, zero-based
 	 */
 	void change_channel(uint8_t channel);
@@ -305,7 +305,7 @@ class MidiRegionView : public RegionView
 	                Gdk::Color& basic_color,
 	                TimeAxisViewItem::Visibility);
 
-	void region_resized (PBD::Change);
+	void region_resized (PBD::PropertyChange);
 
 	void set_flags (XMLNode *);
 	void store_flags ();
diff --git a/gtk2_ardour/midi_streamview.cc b/gtk2_ardour/midi_streamview.cc
index 2982772a62..19c1a53b39 100644
--- a/gtk2_ardour/midi_streamview.cc
+++ b/gtk2_ardour/midi_streamview.cc
@@ -413,9 +413,16 @@ MidiStreamView::setup_rec_box ()
 					start = rec_regions.back().first->start()
 							+ _trackview.get_diskstream()->get_captured_frames(rec_regions.size()-1);
 				}
+				
+				PropertyList plist; 
+				
+				plist.add (ARDOUR::Properties::start, start);
+				plist.add (ARDOUR::Properties::length, 1);
+				plist.add (ARDOUR::Properties::name, string());
+				plist.add (ARDOUR::Properties::layer, 0);
 
 				boost::shared_ptr<MidiRegion> region (boost::dynamic_pointer_cast<MidiRegion>
-					(RegionFactory::create (sources, start, 1 , "", 0, Region::DefaultFlags, false)));
+								      (RegionFactory::create (sources, plist, false)));
 
 				assert(region);
 				region->block_property_changes ();
diff --git a/gtk2_ardour/midi_time_axis.cc b/gtk2_ardour/midi_time_axis.cc
index d1a60ce04a..b1adb7c67e 100644
--- a/gtk2_ardour/midi_time_axis.cc
+++ b/gtk2_ardour/midi_time_axis.cc
@@ -395,7 +395,7 @@ MidiTimeAxisView::build_automation_action_menu ()
 		   something about MIDI (!) would not expect to find them there.
 		*/
 
-		add_channel_command_menu_item (automation_items, _("Program Change"), MidiPgmChangeAutomation, MIDI_CMD_PGM_CHANGE);
+		add_channel_command_menu_item (automation_items, _("Program PropertyChange"), MidiPgmChangeAutomation, MIDI_CMD_PGM_CHANGE);
 		add_channel_command_menu_item (automation_items, _("Bender"), MidiPitchBenderAutomation, MIDI_CMD_BENDER);
 		add_channel_command_menu_item (automation_items, _("Pressure"), MidiChannelPressureAutomation, MIDI_CMD_CHANNEL_PRESSURE);
 		
@@ -968,7 +968,7 @@ MidiTimeAxisView::add_region (nframes64_t pos)
 	real_editor->begin_reversible_command (_("create region"));
 	XMLNode &before = playlist()->get_state();
 
-	nframes64_t start = pos;
+	framepos_t start = pos;
 	real_editor->snap_to (start, -1);
 	const Meter& m = _session->tempo_map().meter_at(start);
 	const Tempo& t = _session->tempo_map().tempo_at(start);
@@ -979,8 +979,13 @@ MidiTimeAxisView::add_region (nframes64_t pos)
 
 	boost::shared_ptr<Source> src = _session->create_midi_source_for_session (*diskstream.get());
 
-	boost::shared_ptr<Region> region = (RegionFactory::create (src, 0, (nframes_t) length,
-								   PBD::basename_nosuffix(src->name())));
+	PropertyList plist; 
+	
+	plist.add (ARDOUR::Properties::start, 0);
+	plist.add (ARDOUR::Properties::length, length);
+	plist.add (ARDOUR::Properties::name, PBD::basename_nosuffix(src->name()));
+	
+	boost::shared_ptr<Region> region = (RegionFactory::create (src, plist));
 
 	playlist()->add_region (region, start);
 	XMLNode &after = playlist()->get_state();
diff --git a/gtk2_ardour/midi_tracer.cc b/gtk2_ardour/midi_tracer.cc
index c757ea3fff..08e1af68e1 100644
--- a/gtk2_ardour/midi_tracer.cc
+++ b/gtk2_ardour/midi_tracer.cc
@@ -143,9 +143,9 @@ MidiTracer::tracer (Parser&, byte* msg, size_t len)
 		
 	case program:
 		if (show_hex) {
-			s += snprintf (&buf[s], bufsize, "%16s chn %2d %02x\n", "Program Change", (msg[0]&0xf)+1, (int) msg[1]);
+			s += snprintf (&buf[s], bufsize, "%16s chn %2d %02x\n", "Program PropertyChange", (msg[0]&0xf)+1, (int) msg[1]);
 		} else {
-			s += snprintf (&buf[s], bufsize, "%16s chn %2d %-3d\n", "Program Change", (msg[0]&0xf)+1, (int) msg[1]);
+			s += snprintf (&buf[s], bufsize, "%16s chn %2d %-3d\n", "Program PropertyChange", (msg[0]&0xf)+1, (int) msg[1]);
 		}
 		break;
 		
diff --git a/gtk2_ardour/mixer_group_tabs.cc b/gtk2_ardour/mixer_group_tabs.cc
index 861a4fd2da..2563adb1d6 100644
--- a/gtk2_ardour/mixer_group_tabs.cc
+++ b/gtk2_ardour/mixer_group_tabs.cc
@@ -29,6 +29,7 @@
 using namespace std;
 using namespace Gtk;
 using namespace ARDOUR;
+using namespace PBD;
 
 MixerGroupTabs::MixerGroupTabs (Mixer_UI* m)
 	: GroupTabs (0),
@@ -200,12 +201,16 @@ MixerGroupTabs::destroy_subgroup (RouteGroup* g)
 ARDOUR::RouteGroup *
 MixerGroupTabs::new_route_group () const
 {
-	RouteGroup* g = new RouteGroup (
-		*_session,
-		"",
-		RouteGroup::Active,
-		(RouteGroup::Property) (RouteGroup::Gain | RouteGroup::Mute | RouteGroup::Solo | RouteGroup::RecEnable)
-		);
+	PropertyList plist;
+
+	plist.add (Properties::active, true);
+	plist.add (Properties::mute, true);
+	plist.add (Properties::solo, true);
+	plist.add (Properties::gain, true);
+	plist.add (Properties::recenable, true);
+
+	RouteGroup* g = new RouteGroup (*_session, "");
+	g->set_properties (plist);
 
 	RouteGroupDialog d (g, Gtk::Stock::NEW);
 	int const r = d.do_run ();
diff --git a/gtk2_ardour/mixer_strip.cc b/gtk2_ardour/mixer_strip.cc
index 94c876cfcd..5be6ec9f5a 100644
--- a/gtk2_ardour/mixer_strip.cc
+++ b/gtk2_ardour/mixer_strip.cc
@@ -1295,11 +1295,13 @@ MixerStrip::select_route_group (GdkEventButton *ev)
 
 		if (group_menu == 0) {
 
-			group_menu = new RouteGroupMenu (
-				_session,
-				(RouteGroup::Property) (RouteGroup::Gain | RouteGroup::Mute | RouteGroup::Solo)
-				);
+			PropertyList* plist = new PropertyList();
 
+			plist->add (Properties::gain, true);
+			plist->add (Properties::mute, true);
+			plist->add (Properties::solo, true);
+
+			group_menu = new RouteGroupMenu (_session, plist);
 			group_menu->GroupSelected.connect (sigc::mem_fun (*this, &MixerStrip::set_route_group));
 		}
 
diff --git a/gtk2_ardour/mixer_ui.cc b/gtk2_ardour/mixer_ui.cc
index 10aa98995d..03b1dd7d69 100644
--- a/gtk2_ardour/mixer_ui.cc
+++ b/gtk2_ardour/mixer_ui.cc
@@ -1131,7 +1131,17 @@ Mixer_UI::route_groups_changed ()
 void
 Mixer_UI::new_route_group ()
 {
-	_session->add_route_group (new RouteGroup (*_session, "", RouteGroup::Active, (RouteGroup::Property) (RouteGroup::Gain |RouteGroup::Mute | RouteGroup::Solo)));
+	PropertyList plist;
+
+	plist.add (Properties::active, true);
+	plist.add (Properties::gain, true);
+	plist.add (Properties::mute, true);
+	plist.add (Properties::solo, true);
+
+	RouteGroup* g = new RouteGroup (*_session, "");
+	g->set_properties (plist);
+
+	_session->add_route_group (g);
 }
 
 void
diff --git a/gtk2_ardour/public_editor.h b/gtk2_ardour/public_editor.h
index 9b41977f6f..24a62e5113 100644
--- a/gtk2_ardour/public_editor.h
+++ b/gtk2_ardour/public_editor.h
@@ -275,7 +275,7 @@ class PublicEditor : public Gtk::Window, public PBD::StatefulDestructible {
 
 	virtual RouteTimeAxisView* get_route_view_by_id (PBD::ID& id) = 0;
 
-	virtual void get_equivalent_regions (RegionView* rv, std::vector<RegionView*>&, ARDOUR::RouteGroup::Property) const = 0;
+	virtual void get_equivalent_regions (RegionView* rv, std::vector<RegionView*>&, PBD::PropertyID) const = 0;
 
 	sigc::signal<void> ZoomFocusChanged;
 	sigc::signal<void> ZoomChanged;
diff --git a/gtk2_ardour/quantize_dialog.cc b/gtk2_ardour/quantize_dialog.cc
index f8a6d3a516..727f2b0db9 100644
--- a/gtk2_ardour/quantize_dialog.cc
+++ b/gtk2_ardour/quantize_dialog.cc
@@ -20,6 +20,7 @@
 #include <gtkmm/stock.h>
 #include "gtkmm2ext/utils.h"
 
+#include "pbd/convert.h"
 #include "quantize_dialog.h"
 #include "public_editor.h"
 
diff --git a/gtk2_ardour/region_view.cc b/gtk2_ardour/region_view.cc
index e9b3da554d..575ecbb5e2 100644
--- a/gtk2_ardour/region_view.cc
+++ b/gtk2_ardour/region_view.cc
@@ -228,7 +228,7 @@ RegionView::lock_toggle ()
 }
 
 void
-RegionView::region_changed (Change what_changed)
+RegionView::region_changed (PropertyChange what_changed)
 {
 	ENSURE_GUI_THREAD (*this, &RegionView::region_changed, what_changed)
 
@@ -261,7 +261,7 @@ RegionView::region_locked ()
 }
 
 void
-RegionView::region_resized (Change what_changed)
+RegionView::region_resized (PropertyChange what_changed)
 {
 	double unit_length;
 
@@ -270,7 +270,7 @@ RegionView::region_resized (Change what_changed)
 		_time_converter.set_origin(_region->position());
 	}
 
-	if (what_changed & Change (StartChanged|LengthChanged)) {
+	if (what_changed & PropertyChange (StartChanged|LengthChanged)) {
 
 		set_duration (_region->length(), 0);
 
diff --git a/gtk2_ardour/region_view.h b/gtk2_ardour/region_view.h
index 172405d132..d9ffc83c50 100644
--- a/gtk2_ardour/region_view.h
+++ b/gtk2_ardour/region_view.h
@@ -75,7 +75,7 @@ class RegionView : public TimeAxisViewItem
 	virtual void show_region_editor () {}
 	virtual void hide_region_editor();
 
-	virtual void region_changed (PBD::Change);
+	virtual void region_changed (PBD::PropertyChange);
 
 	virtual GhostRegion* add_ghost (TimeAxisView&) = 0;
 	void remove_ghost_in (TimeAxisView&);
@@ -104,7 +104,7 @@ class RegionView : public TimeAxisViewItem
 		bool recording,
 		TimeAxisViewItem::Visibility);
 
-    virtual void region_resized (PBD::Change);
+    virtual void region_resized (PBD::PropertyChange);
     virtual void region_muted ();
     void         region_locked ();
     void         region_opacity ();
diff --git a/gtk2_ardour/route_group_dialog.cc b/gtk2_ardour/route_group_dialog.cc
index 94caef9286..7b802ac6ec 100644
--- a/gtk2_ardour/route_group_dialog.cc
+++ b/gtk2_ardour/route_group_dialog.cc
@@ -27,6 +27,7 @@
 using namespace Gtk;
 using namespace ARDOUR;
 using namespace std;
+using namespace PBD;
 
 RouteGroupDialog::RouteGroupDialog (RouteGroup* g, StockID const & s)
 	: ArdourDialog (_("route group dialog")),
@@ -77,13 +78,13 @@ RouteGroupDialog::RouteGroupDialog (RouteGroup* g, StockID const & s)
 
 	_name.signal_activate ().connect (sigc::bind (sigc::mem_fun (*this, &Dialog::response), RESPONSE_OK));
 
-	_gain.set_active (_group->property (RouteGroup::Gain));
+	_gain.set_active (_group->is_gain());
 	_relative.set_active (_group->is_relative());
-	_mute.set_active (_group->property (RouteGroup::Mute));
-	_solo.set_active (_group->property (RouteGroup::Solo));
-	_rec_enable.set_active (_group->property (RouteGroup::RecEnable));
-	_select.set_active (_group->property (RouteGroup::Select));
-	_edit.set_active (_group->property (RouteGroup::Edit));
+	_mute.set_active (_group->is_mute());
+	_solo.set_active (_group->is_solo());
+	_rec_enable.set_active (_group->is_recenable());
+	_select.set_active (_group->is_select());
+	_edit.set_active (_group->is_edit());
 
 	gain_toggled ();
 
@@ -128,15 +129,20 @@ RouteGroupDialog::do_run ()
 	int const r = run ();
 
 	if (r == Gtk::RESPONSE_OK || r == Gtk::RESPONSE_ACCEPT) {
-		_group->set_property (RouteGroup::Gain, _gain.get_active ());
-		_group->set_property (RouteGroup::Mute, _mute.get_active ());
-		_group->set_property (RouteGroup::Solo, _solo.get_active ());
-		_group->set_property (RouteGroup::RecEnable, _rec_enable.get_active ());
-		_group->set_property (RouteGroup::Select, _select.get_active ());
-		_group->set_property (RouteGroup::Edit, _edit.get_active ());
-		_group->set_name (_name.get_text ()); // This emits changed signal
-		_group->set_active (_active.get_active (), this);
-		_group->set_relative (_relative.get_active(), this);
+
+		PropertyList plist;
+
+		plist.add (Properties::gain, _gain.get_active());
+		plist.add (Properties::recenable, _rec_enable.get_active());
+		plist.add (Properties::mute, _mute.get_active());
+		plist.add (Properties::solo, _solo.get_active ());
+		plist.add (Properties::select, _select.get_active());
+		plist.add (Properties::edit, _edit.get_active());
+		plist.add (Properties::relative, _relative.get_active());
+		plist.add (Properties::active, _active.get_active());
+		plist.add (Properties::name, string (_name.get_text()));
+		
+		_group->set_properties (plist);
 	}
 
 	return r;
diff --git a/gtk2_ardour/route_group_menu.cc b/gtk2_ardour/route_group_menu.cc
index c8ef0a260b..baf383be5d 100644
--- a/gtk2_ardour/route_group_menu.cc
+++ b/gtk2_ardour/route_group_menu.cc
@@ -27,16 +27,22 @@
 
 using namespace Gtk;
 using namespace ARDOUR;
+using namespace PBD;
 
-RouteGroupMenu::RouteGroupMenu (Session* s, RouteGroup::Property p)
+RouteGroupMenu::RouteGroupMenu (Session* s, PropertyList* plist)
 	: SessionHandlePtr (s)
-	, _default_properties (p)
+	, _default_properties (plist)
 	, _inhibit_group_selected (false)
 	, _selected_route_group (0)
 {
 	rebuild (0);
 }
 
+RouteGroupMenu::~RouteGroupMenu()
+{
+	delete _default_properties; 
+}
+
 void
 RouteGroupMenu::rebuild (RouteGroup* curr)
 {
@@ -101,7 +107,8 @@ RouteGroupMenu::new_group ()
 		return;
 	}
 
-	RouteGroup* g = new RouteGroup (*_session, "", RouteGroup::Active, _default_properties);
+	RouteGroup* g = new RouteGroup (*_session, "");
+	g->set_properties (*_default_properties);
 
 	RouteGroupDialog d (g, Gtk::Stock::NEW);
 	int const r = d.do_run ();
diff --git a/gtk2_ardour/route_group_menu.h b/gtk2_ardour/route_group_menu.h
index 1fbbbcf7b3..b588be7838 100644
--- a/gtk2_ardour/route_group_menu.h
+++ b/gtk2_ardour/route_group_menu.h
@@ -27,7 +27,8 @@
 class RouteGroupMenu : public Gtk::Menu, public ARDOUR::SessionHandlePtr
 {
 public:
-	RouteGroupMenu (ARDOUR::Session*, ARDOUR::RouteGroup::Property);
+	RouteGroupMenu (ARDOUR::Session*, PBD::PropertyList*);
+	~RouteGroupMenu();
 
 	void rebuild (ARDOUR::RouteGroup *);
 
@@ -38,7 +39,7 @@ public:
 	void new_group ();
 	void set_group (ARDOUR::RouteGroup *);
 
-	ARDOUR::RouteGroup::Property _default_properties;
+	PBD::PropertyList* _default_properties;
 	bool _inhibit_group_selected;
 	ARDOUR::RouteGroup* _selected_route_group;
 };
diff --git a/gtk2_ardour/route_time_axis.cc b/gtk2_ardour/route_time_axis.cc
index 8de2f6b141..0b5cf8b085 100644
--- a/gtk2_ardour/route_time_axis.cc
+++ b/gtk2_ardour/route_time_axis.cc
@@ -248,11 +248,13 @@ RouteTimeAxisView::RouteTimeAxisView (PublicEditor& ed, Session* sess, boost::sh
 	_editor.ZoomChanged.connect (sigc::mem_fun(*this, &RouteTimeAxisView::reset_samples_per_unit));
 	ColorsChanged.connect (sigc::mem_fun (*this, &RouteTimeAxisView::color_handler));
 
-	route_group_menu = new RouteGroupMenu (
-		_session,
-		(RouteGroup::Property) (RouteGroup::Mute | RouteGroup::Solo | RouteGroup::Edit)
-		);
-
+	PropertyList* plist = new PropertyList();
+	
+	plist->add (ARDOUR::Properties::edit, true);
+	plist->add (ARDOUR::Properties::mute, true);
+	plist->add (ARDOUR::Properties::solo, true);
+	
+	route_group_menu = new RouteGroupMenu (_session, plist);
 	route_group_menu->GroupSelected.connect (sigc::mem_fun (*this, &RouteTimeAxisView::set_route_group_from_menu));
 
 	gm.get_gain_slider().signal_scroll_event().connect(sigc::mem_fun(*this, &RouteTimeAxisView::controls_ebox_scroll), false);
diff --git a/gtk2_ardour/route_ui.h b/gtk2_ardour/route_ui.h
index 12a1cde703..5dce9ee4b4 100644
--- a/gtk2_ardour/route_ui.h
+++ b/gtk2_ardour/route_ui.h
@@ -205,7 +205,6 @@ class RouteUI : public virtual AxisView
  	void init ();
  	void reset ();
 
-	void queue_route_group_op (ARDOUR::RouteGroup::Property prop, void (ARDOUR::Session::*session_method)(boost::shared_ptr<ARDOUR::RouteList>, bool), bool yn);
 	void self_delete ();
 
   private:
diff --git a/gtk2_ardour/sfdb_ui.cc b/gtk2_ardour/sfdb_ui.cc
index 6919be9f62..65ae061e5c 100644
--- a/gtk2_ardour/sfdb_ui.cc
+++ b/gtk2_ardour/sfdb_ui.cc
@@ -347,9 +347,15 @@ SoundFileBox::audition ()
 
 	afs = boost::dynamic_pointer_cast<AudioFileSource> (srclist[0]);
 	string rname = region_name_from_path (afs->path(), false);
-	r = boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (srclist, 0,
-				srclist[0]->length(srclist[0]->timeline_position()),
-				rname, 0, Region::DefaultFlags, false));
+	
+	PropertyList plist; 
+	
+	plist.add (ARDOUR::Properties::start, 0);
+	plist.add (ARDOUR::Properties::length, srclist[0]->length(srclist[0]->timeline_position()));
+	plist.add (ARDOUR::Properties::name, rname);
+	plist.add (ARDOUR::Properties::layer, 0);
+	
+	r = boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (srclist, plist, false));
 
 	_session->audition_region(r);
 }
diff --git a/gtk2_ardour/strip_silence_dialog.cc b/gtk2_ardour/strip_silence_dialog.cc
index 3592668cf8..2be04f7fcb 100644
--- a/gtk2_ardour/strip_silence_dialog.cc
+++ b/gtk2_ardour/strip_silence_dialog.cc
@@ -33,6 +33,8 @@
 #include "rgb_macros.h"
 #include "i18n.h"
 
+using namespace ARDOUR;
+
 /** Construct Strip silence dialog box */
 StripSilenceDialog::StripSilenceDialog (std::list<boost::shared_ptr<ARDOUR::AudioRegion> > const & regions)
 	: ArdourDialog (_("Strip Silence")), _wave_width (640), _wave_height (64)
@@ -183,10 +185,10 @@ StripSilenceDialog::update_silence_rects ()
 
 		i->silence_rects.clear ();
 
-		std::list<std::pair<nframes_t, nframes_t> > const silence =
+		std::list<std::pair<frameoffset_t, framecnt_t> > const silence =
 			i->region->find_silence (dB_to_coefficient (threshold ()), minimum_length ());
-
-		for (std::list<std::pair<nframes_t, nframes_t> >::const_iterator j = silence.begin(); j != silence.end(); ++j) {
+		
+		for (std::list<std::pair<frameoffset_t, framecnt_t> >::const_iterator j = silence.begin(); j != silence.end(); ++j) {
 
 			ArdourCanvas::SimpleRect* r = new ArdourCanvas::SimpleRect (*(_canvas->root()));
 			r->property_x1() = j->first / i->samples_per_unit;
diff --git a/gtk2_ardour/track_selection.cc b/gtk2_ardour/track_selection.cc
index 9aa29bdb6d..95ca1253b8 100755
--- a/gtk2_ardour/track_selection.cc
+++ b/gtk2_ardour/track_selection.cc
@@ -41,7 +41,7 @@ TrackSelection::add (TrackViewList const & t)
 
 		/* select anything in the same select-enabled route group */
 		ARDOUR::RouteGroup* rg = (*i)->route_group ();
-		if (rg && rg->property (ARDOUR::RouteGroup::Select)) {
+		if (rg && rg->is_active() && rg->is_select ()) {
 			TrackViewList tr = _editor->axis_views_from_routes (rg->route_list ());
 			for (TrackViewList::iterator j = tr.begin(); j != tr.end(); ++j) {
 				if (!contains (*j)) {
diff --git a/libs/ardour/ardour/ardour.h b/libs/ardour/ardour/ardour.h
index 403cf21007..f608db5b7e 100644
--- a/libs/ardour/ardour/ardour.h
+++ b/libs/ardour/ardour/ardour.h
@@ -65,12 +65,11 @@ namespace ARDOUR {
 		return (microseconds_t) jack_get_time();
 	}
 
-	extern PBD::Change StartChanged;
-	extern PBD::Change LengthChanged;
-	extern PBD::Change PositionChanged;
-	extern PBD::Change NameChanged;
-	extern PBD::Change BoundsChanged;
-	extern PBD::Change FlagsChanged;
+	extern PBD::PropertyChange StartChanged;
+	extern PBD::PropertyChange LengthChanged;
+	extern PBD::PropertyChange PositionChanged;
+	extern PBD::PropertyChange NameChanged;
+	extern PBD::PropertyChange BoundsChanged;
 
 	static const double SHUTTLE_FRACT_SPEED1=0.48412291827; /* derived from A1,A2 */
 
diff --git a/libs/ardour/ardour/audioplaylist.h b/libs/ardour/ardour/audioplaylist.h
index ce7c8aa335..b5df4cfabb 100644
--- a/libs/ardour/ardour/audioplaylist.h
+++ b/libs/ardour/ardour/audioplaylist.h
@@ -79,8 +79,8 @@ class AudioPlaylist : public ARDOUR::Playlist
        XMLNode& state (bool full_state);
        void dump () const;
 
-       bool region_changed (PBD::Change, boost::shared_ptr<Region>);
-       void crossfade_changed (PBD::Change);
+       bool region_changed (PBD::PropertyChange, boost::shared_ptr<Region>);
+       void crossfade_changed (PBD::PropertyChange);
        void add_crossfade (boost::shared_ptr<Crossfade>);
 
        void source_offset_changed (boost::shared_ptr<AudioRegion> region);
diff --git a/libs/ardour/ardour/audioregion.h b/libs/ardour/ardour/audioregion.h
index 3f1e4cf9e3..711c8030bd 100644
--- a/libs/ardour/ardour/audioregion.h
+++ b/libs/ardour/ardour/audioregion.h
@@ -34,24 +34,37 @@
 
 class XMLNode;
 
+
 namespace ARDOUR {
 
+namespace Properties {
+	extern PBD::PropertyDescriptor<bool> envelope_active;
+	extern PBD::PropertyDescriptor<bool> default_fade_in;
+	extern PBD::PropertyDescriptor<bool> default_fade_out;
+	extern PBD::PropertyDescriptor<bool> fade_in_active;
+	extern PBD::PropertyDescriptor<bool> fade_out_active;
+	extern PBD::PropertyDescriptor<float> scale_amplitude;
+}
+
 class Route;
 class Playlist;
 class Session;
 class Filter;
 class AudioSource;
 
+
 class AudioRegion : public Region
 {
   public:
-	static PBD::Change FadeInChanged;
-	static PBD::Change FadeOutChanged;
-	static PBD::Change FadeInActiveChanged;
-	static PBD::Change FadeOutActiveChanged;
-	static PBD::Change EnvelopeActiveChanged;
-	static PBD::Change ScaleAmplitudeChanged;
-	static PBD::Change EnvelopeChanged;
+	static void make_property_quarks ();
+
+	static PBD::PropertyChange FadeInChanged;
+	static PBD::PropertyChange FadeOutChanged;
+	static PBD::PropertyChange FadeInActiveChanged;
+	static PBD::PropertyChange FadeOutActiveChanged;
+	static PBD::PropertyChange EnvelopeActiveChanged;
+	static PBD::PropertyChange ScaleAmplitudeChanged;
+	static PBD::PropertyChange EnvelopeChanged;
 
 	~AudioRegion();
 
@@ -68,9 +81,9 @@ class AudioRegion : public Region
 
 	void normalize_to (float target_in_dB = 0.0f);
 
-	bool envelope_active () const { return _flags & Region::EnvelopeActive; }
-	bool fade_in_active ()  const { return _flags & Region::FadeIn; }
-	bool fade_out_active () const { return _flags & Region::FadeOut; }
+	bool envelope_active () const { return _envelope_active; }
+	bool fade_in_active ()  const { return _fade_in_active; }
+	bool fade_out_active () const { return _fade_out_active; }
 
 	boost::shared_ptr<AutomationList> fade_in()  { return _fade_in; }
 	boost::shared_ptr<AutomationList> fade_out() { return _fade_out; }
@@ -90,26 +103,26 @@ class AudioRegion : public Region
 		ReadOpsFades = 0x8
 	};
 
-	virtual nframes_t read (Sample*, sframes_t pos, nframes_t cnt, int channel) const;
-	virtual nframes_t read_with_ops (Sample*, sframes_t pos, nframes_t cnt, int channel, ReadOps rops) const;
-	virtual nframes64_t readable_length() const { return length(); }
-
-	virtual nframes_t read_at (Sample *buf, Sample *mixdown_buf, float *gain_buf,
-			sframes_t position,
-			nframes_t cnt,
-			uint32_t  chan_n      = 0,
-			nframes_t read_frames = 0,
-			nframes_t skip_frames = 0) const;
-
-	virtual nframes_t master_read_at (Sample *buf, Sample *mixdown_buf, float *gain_buf,
-			sframes_t position, nframes_t cnt, uint32_t chan_n=0) const;
-
-	virtual nframes_t read_raw_internal (Sample*, sframes_t, nframes_t, int channel) const;
+	virtual framecnt_t read (Sample*, framepos_t pos, framecnt_t cnt, int channel) const;
+	virtual framecnt_t read_with_ops (Sample*, framepos_t pos, framecnt_t cnt, int channel, ReadOps rops) const;
+	virtual framecnt_t readable_length() const { return length(); }
+
+	virtual framecnt_t read_at (Sample *buf, Sample *mixdown_buf, float *gain_buf,
+				     framepos_t position,
+				     framecnt_t cnt,
+				     uint32_t  chan_n      = 0,
+				     framecnt_t read_frames = 0,
+				     framecnt_t skip_frames = 0) const;
+	
+	virtual framecnt_t master_read_at (Sample *buf, Sample *mixdown_buf, float *gain_buf,
+					   framepos_t position, framecnt_t cnt, uint32_t chan_n=0) const;
+	
+	virtual framecnt_t read_raw_internal (Sample*, framepos_t, framecnt_t, int channel) const;
 
 	XMLNode& state (bool);
-	int      set_state (const XMLNode&, int version);
+	int set_state (const XMLNode&, int version);
 
-	static void set_default_fade (float steepness, nframes_t len);
+	static void set_default_fade (float steepness, framecnt_t len);
 	bool fade_in_is_default () const;
 	bool fade_out_is_default () const;
 
@@ -123,14 +136,14 @@ class AudioRegion : public Region
 
 	void set_fade_in_active (bool yn);
 	void set_fade_in_shape (FadeShape);
-	void set_fade_in_length (nframes_t);
-	void set_fade_in (FadeShape, nframes_t);
+	void set_fade_in_length (framecnt_t);
+	void set_fade_in (FadeShape, framecnt_t);
 	void set_fade_in (boost::shared_ptr<AutomationList>);
 
 	void set_fade_out_active (bool yn);
 	void set_fade_out_shape (FadeShape);
-	void set_fade_out_length (nframes_t);
-	void set_fade_out (FadeShape, nframes_t);
+	void set_fade_out_length (framecnt_t);
+	void set_fade_out (FadeShape, framecnt_t);
 	void set_fade_out (boost::shared_ptr<AutomationList>);
 
 	void set_envelope_active (bool yn);
@@ -162,22 +175,31 @@ class AudioRegion : public Region
 	void resume_fade_out ();
 
 	int get_transients (AnalysisFeatureList&, bool force_new = false);
-	std::list<std::pair<nframes_t, nframes_t> > find_silence (Sample, nframes_t) const;
+	std::list<std::pair<frameoffset_t, framecnt_t> > find_silence (Sample, framecnt_t) const;
 
   private:
 	friend class RegionFactory;
 	friend class Crossfade;
 
-	AudioRegion (boost::shared_ptr<AudioSource>, nframes_t start, nframes_t length);
-	AudioRegion (boost::shared_ptr<AudioSource>, nframes_t start, nframes_t length, const std::string& name, layer_t = 0, Region::Flag flags = Region::DefaultFlags);
-	AudioRegion (const SourceList &, nframes_t start, nframes_t length, const std::string& name, layer_t = 0, Region::Flag flags = Region::DefaultFlags);
-	AudioRegion (boost::shared_ptr<const AudioRegion>, nframes_t start, nframes_t length, const std::string& name, layer_t = 0, Region::Flag flags = Region::DefaultFlags);
-	AudioRegion (boost::shared_ptr<const AudioRegion>, const SourceList&, nframes_t length, const std::string& name, layer_t = 0, Region::Flag flags = Region::DefaultFlags);
-	AudioRegion (boost::shared_ptr<const AudioRegion>);
+	AudioRegion (boost::shared_ptr<AudioSource>);
+	AudioRegion (const SourceList &);
+	AudioRegion (boost::shared_ptr<const AudioRegion>, frameoffset_t offset = 0, bool offset_relative = true);
+	AudioRegion (boost::shared_ptr<const AudioRegion>, const SourceList&);
 	AudioRegion (boost::shared_ptr<AudioSource>, const XMLNode&);
 	AudioRegion (SourceList &, const XMLNode&);
 
   private:
+	PBD::Property<bool>     _envelope_active;
+	PBD::Property<bool>     _default_fade_in;
+	PBD::Property<bool>     _default_fade_out;
+	PBD::Property<bool>     _fade_in_active;
+	PBD::Property<bool>     _fade_out_active;
+	PBD::Property<gain_t>   _scale_amplitude;
+	
+	void register_properties ();
+	PBD::PropertyChange set_property (const PBD::PropertyBase& prop);
+	void post_set ();
+
 	void init ();
 	void set_default_fades ();
 	void set_default_fade_in ();
@@ -186,13 +208,13 @@ class AudioRegion : public Region
 	void recompute_gain_at_end ();
 	void recompute_gain_at_start ();
 
-	nframes_t _read_at (const SourceList&, nframes_t limit,
-			Sample *buf, Sample *mixdown_buffer, float *gain_buffer,
-			sframes_t position, nframes_t cnt,
-			uint32_t chan_n = 0,
-			nframes_t read_frames = 0,
-			nframes_t skip_frames = 0,
-			ReadOps readops = ReadOps (~0)) const;
+	framecnt_t _read_at (const SourceList&, framecnt_t limit,
+			     Sample *buf, Sample *mixdown_buffer, float *gain_buffer,
+			     framepos_t position, framecnt_t cnt,
+			     uint32_t chan_n = 0,
+			     framecnt_t read_frames = 0,
+			     framecnt_t skip_frames = 0,
+			     ReadOps readops = ReadOps (~0)) const;
 
 	void recompute_at_start ();
 	void recompute_at_end ();
@@ -210,16 +232,15 @@ class AudioRegion : public Region
 	boost::shared_ptr<AutomationList> _fade_in;
 	boost::shared_ptr<AutomationList> _fade_out;
 	boost::shared_ptr<AutomationList> _envelope;
-	gain_t                            _scale_amplitude;
-	uint32_t                          _fade_in_disabled;
-	uint32_t                          _fade_out_disabled;
+	uint32_t                          _fade_in_suspended;
+	uint32_t                          _fade_out_suspended;
 
   protected:
 	/* default constructor for derived (compound) types */
 
-	AudioRegion (Session& s, nframes_t, nframes_t, std::string name);
+	AudioRegion (Session& s, framepos_t, framecnt_t, std::string name);
 
-	int set_live_state (const XMLNode&, int version, PBD::Change&, bool send);
+	int _set_state (const XMLNode&, int version, PBD::PropertyChange& what_changed, bool send_signal);
 };
 
 } /* namespace ARDOUR */
diff --git a/libs/ardour/ardour/audiosource.h b/libs/ardour/ardour/audiosource.h
index 45f62fc7b9..c39dbdfd8c 100644
--- a/libs/ardour/ardour/audiosource.h
+++ b/libs/ardour/ardour/audiosource.h
@@ -45,16 +45,16 @@ class AudioSource : virtual public Source,
 	AudioSource (Session&, const XMLNode&);
 	virtual ~AudioSource ();
 
-	nframes64_t readable_length() const { return _length; }
-	uint32_t    n_channels()      const { return 1; }
+	framecnt_t readable_length() const { return _length; }
+	uint32_t   n_channels()      const { return 1; }
 
-	sframes_t length (sframes_t pos) const;
-	void      update_length (sframes_t pos, sframes_t cnt);
+	framecnt_t length (framepos_t pos) const;
+	void      update_length (framepos_t pos, framecnt_t cnt);
 
-	virtual nframes_t available_peaks (double zoom) const;
+	virtual framecnt_t available_peaks (double zoom) const;
 
-	virtual nframes_t read (Sample *dst, sframes_t start, nframes_t cnt, int channel=0) const;
-	virtual nframes_t write (Sample *src, nframes_t cnt);
+	virtual framecnt_t read (Sample *dst, framepos_t start, framecnt_t cnt, int channel=0) const;
+	virtual framecnt_t write (Sample *src, framecnt_t cnt);
 
 	virtual float sample_rate () const = 0;
 
@@ -68,14 +68,14 @@ class AudioSource : virtual public Source,
 	uint32_t read_data_count() const { return _read_data_count; }
 	uint32_t write_data_count() const { return _write_data_count; }
 
-	int read_peaks (PeakData *peaks, nframes_t npeaks,
-			sframes_t start, nframes_t cnt, double samples_per_visual_peak) const;
+	int read_peaks (PeakData *peaks, framecnt_t npeaks,
+			framepos_t start, framecnt_t cnt, double samples_per_visual_peak) const;
 
 	int  build_peaks ();
 	bool peaks_ready (boost::function<void()> callWhenReady, PBD::Connection& connection_created_if_not_ready, PBD::EventLoop* event_loop) const;
 
 	mutable PBD::Signal0<void>  PeaksReady;
-	mutable PBD::Signal2<void,nframes_t,nframes_t>  PeakRangeReady;
+	mutable PBD::Signal2<void,framepos_t,framepos_t>  PeakRangeReady;
 
 	XMLNode& get_state ();
 	int set_state (const XMLNode&, int version);
@@ -104,7 +104,7 @@ class AudioSource : virtual public Source,
 	static bool _build_missing_peakfiles;
 	static bool _build_peakfiles;
 
-	sframes_t            _length;
+	framecnt_t           _length;
 	bool                 _peaks_built;
 	mutable Glib::Mutex  _peaks_ready_lock;
 	Glib::ustring         peakpath;
@@ -115,31 +115,32 @@ class AudioSource : virtual public Source,
 
 	int initialize_peakfile (bool newfile, Glib::ustring path);
 	int build_peaks_from_scratch ();
-	int compute_and_write_peaks (Sample* buf, sframes_t first_frame, nframes_t cnt,
+	int compute_and_write_peaks (Sample* buf, framepos_t first_frame, framecnt_t cnt,
 	bool force, bool intermediate_peaks_ready_signal);
 	void truncate_peakfile();
 
 	mutable off_t _peak_byte_max; // modified in compute_and_write_peak()
 
-	virtual nframes_t read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const = 0;
-	virtual nframes_t write_unlocked (Sample *dst, nframes_t cnt) = 0;
+	virtual framecnt_t read_unlocked (Sample *dst, framepos_t start, framecnt_t cnt) const = 0;
+	virtual framecnt_t write_unlocked (Sample *dst, framecnt_t cnt) = 0;
 	virtual Glib::ustring peak_path(Glib::ustring audio_path) = 0;
 	virtual Glib::ustring find_broken_peakfile (Glib::ustring missing_peak_path,
 	                                            Glib::ustring audio_path) = 0;
 
 	virtual int read_peaks_with_fpp (PeakData *peaks,
-	nframes_t npeaks, sframes_t start, nframes_t cnt,
-	double samples_per_visual_peak, nframes_t fpp) const;
-
-	int compute_and_write_peaks (Sample* buf, sframes_t first_frame, nframes_t cnt,
-	bool force, bool intermediate_peaks_ready_signal, nframes_t frames_per_peak);
+					 framecnt_t npeaks, framepos_t start, framecnt_t cnt,
+					 double samples_per_visual_peak, framecnt_t fpp) const;
+	
+	int compute_and_write_peaks (Sample* buf, framepos_t first_frame, framecnt_t cnt,
+				     bool force, bool intermediate_peaks_ready_signal, 
+				     framecnt_t frames_per_peak);
 
   private:
-	int       peakfile;
-	nframes_t peak_leftover_cnt;
-	nframes_t peak_leftover_size;
-	Sample*   peak_leftovers;
-	nframes_t peak_leftover_frame;
+	int        peakfile;
+	framecnt_t peak_leftover_cnt;
+	framecnt_t peak_leftover_size;
+	Sample*    peak_leftovers;
+	framepos_t peak_leftover_frame;
 };
 
 }
diff --git a/libs/ardour/ardour/crossfade.h b/libs/ardour/ardour/crossfade.h
index 148b501e51..15b9b3d2a7 100644
--- a/libs/ardour/ardour/crossfade.h
+++ b/libs/ardour/ardour/crossfade.h
@@ -50,9 +50,9 @@ class Crossfade : public ARDOUR::AudioRegion
 	/* constructor for "fixed" xfades at each end of an internal overlap */
 
 	Crossfade (boost::shared_ptr<ARDOUR::AudioRegion> in, boost::shared_ptr<ARDOUR::AudioRegion> out,
-			nframes_t position,
-			nframes_t initial_length,
-			AnchorPoint);
+		   framepos_t position,
+		   framecnt_t initial_length,
+		   AnchorPoint);
 
 	/* constructor for xfade between two regions that are overlapped in any way
 	   except the "internal" case.
@@ -79,11 +79,11 @@ class Crossfade : public ARDOUR::AudioRegion
 	boost::shared_ptr<ARDOUR::AudioRegion> in() const { return _in; }
 	boost::shared_ptr<ARDOUR::AudioRegion> out() const { return _out; }
 
-	nframes_t read_at (Sample *buf, Sample *mixdown_buffer,
-			float *gain_buffer, sframes_t position, nframes_t cnt,
-			uint32_t chan_n,
-			nframes_t read_frames = 0,
-			nframes_t skip_frames = 0) const;
+	framecnt_t read_at (Sample *buf, Sample *mixdown_buffer,
+			    float *gain_buffer, framepos_t position, framecnt_t cnt,
+			    uint32_t chan_n,
+			    framecnt_t read_frames = 0,
+			    framecnt_t skip_frames = 0) const;
 
 	bool refresh ();
 
@@ -103,18 +103,18 @@ class Crossfade : public ARDOUR::AudioRegion
 		return (_in == a && _out == b) || (_in == b && _out == a);
 	}
 
-	nframes_t overlap_length() const;
+	framecnt_t overlap_length() const;
 
 	PBD::Signal1<void,boost::shared_ptr<Region> > Invalidated;
-	PBD::Signal1<void,PBD::Change>     StateChanged;
+	PBD::Signal1<void,PBD::PropertyChange>     StateChanged;
 
-	bool covers (nframes_t frame) const {
+	bool covers (framecnt_t frame) const {
 		return _position <= frame && frame < _position + _length;
 	}
 
-	OverlapType coverage (nframes_t start, nframes_t end) const;
+	OverlapType coverage (framepos_t start, framepos_t end) const;
 
-	static void set_buffer_size (nframes_t);
+	static void set_buffer_size (framecnt_t);
 
 	bool active () const { return _active; }
 	void set_active (bool yn);
@@ -126,24 +126,24 @@ class Crossfade : public ARDOUR::AudioRegion
 	AutomationList& fade_in() { return _fade_in; }
 	AutomationList& fade_out() { return _fade_out; }
 
-	nframes_t set_xfade_length (nframes_t);
+	framecnt_t set_xfade_length (framecnt_t);
 
 	bool is_dependent() const { return true; }
 	bool depends_on (boost::shared_ptr<Region> other) const {
 		return other == _in || other == _out;
 	}
 
-	static nframes_t short_xfade_length() { return _short_xfade_length; }
-	static void set_short_xfade_length (nframes_t n);
+	static framecnt_t short_xfade_length() { return _short_xfade_length; }
+	static void set_short_xfade_length (framecnt_t n);
 
-	static PBD::Change ActiveChanged;
-	static PBD::Change FollowOverlapChanged;
+	static PBD::PropertyChange ActiveChanged;
+	static PBD::PropertyChange FollowOverlapChanged;
 
   private:
 	friend struct CrossfadeComparePtr;
 	friend class AudioPlaylist;
 
-	static nframes_t _short_xfade_length;
+	static framecnt_t _short_xfade_length;
 
 	boost::shared_ptr<ARDOUR::AudioRegion> _in;
 	boost::shared_ptr<ARDOUR::AudioRegion> _out;
@@ -167,7 +167,7 @@ class Crossfade : public ARDOUR::AudioRegion
 	bool update ();
 
   protected:
-	nframes_t read_raw_internal (Sample*, sframes_t, nframes_t, int) const;
+	framecnt_t read_raw_internal (Sample*, framepos_t, framecnt_t, int) const;
 };
 
 
diff --git a/libs/ardour/ardour/debug.h b/libs/ardour/ardour/debug.h
index 24c6e9915f..b7ee4c328c 100644
--- a/libs/ardour/ardour/debug.h
+++ b/libs/ardour/ardour/debug.h
@@ -52,7 +52,8 @@ namespace ARDOUR {
 			SessionEvents = 0x800,
 			MidiIO = 0x1000,
 			MackieControl = 0x2000,
-			MidiClock = 0x4000
+			MidiClock = 0x4000,
+			Properties = 0x8000
 		};
 	}
 
diff --git a/libs/ardour/ardour/diskstream.h b/libs/ardour/ardour/diskstream.h
index 0c1bbd54d8..90bcf4067a 100644
--- a/libs/ardour/ardour/diskstream.h
+++ b/libs/ardour/ardour/diskstream.h
@@ -141,7 +141,7 @@ class Diskstream : public SessionObject
 	void remove_region_from_last_capture (boost::weak_ptr<Region> wregion);
 
 	void move_processor_automation (boost::weak_ptr<Processor>,
-			std::list< Evoral::RangeMove<nframes_t> > const &);
+			std::list<Evoral::RangeMove<framepos_t> > const &);
 
 	PBD::Signal0<void>            RecordEnableChanged;
 	PBD::Signal0<void>            SpeedChanged;
@@ -206,9 +206,9 @@ class Diskstream : public SessionObject
 
 	/* XXX fix this redundancy ... */
 
-	virtual void playlist_changed (PBD::Change);
+	virtual void playlist_changed (PBD::PropertyChange);
 	virtual void playlist_deleted (boost::weak_ptr<Playlist>);
-	virtual void playlist_ranges_moved (std::list< Evoral::RangeMove<nframes_t> > const &);
+	virtual void playlist_ranges_moved (std::list< Evoral::RangeMove<framepos_t> > const &);
 
 	virtual void transport_stopped (struct tm&, time_t, bool abort) = 0;
 	virtual void transport_looped (nframes_t transport_frame) = 0;
diff --git a/libs/ardour/ardour/location.h b/libs/ardour/ardour/location.h
index 6cec906d28..d93ffeec4a 100644
--- a/libs/ardour/ardour/location.h
+++ b/libs/ardour/ardour/location.h
@@ -179,7 +179,7 @@ class Locations : public PBD::StatefulDestructible
 	PBD::Signal0<void>           changed;
 	PBD::Signal1<void,Location*> added;
 	PBD::Signal1<void,Location*> removed;
-	PBD::Signal1<void,PBD::Change>    StateChanged;
+	PBD::Signal1<void,PBD::PropertyChange>    StateChanged;
 
 	template<class T> void apply (T& obj, void (T::*method)(LocationList&)) {
 		Glib::Mutex::Lock lm (lock);
diff --git a/libs/ardour/ardour/midi_model.h b/libs/ardour/ardour/midi_model.h
index 3cf64da6ea..77f5798898 100644
--- a/libs/ardour/ardour/midi_model.h
+++ b/libs/ardour/ardour/midi_model.h
@@ -90,7 +90,7 @@ public:
 	};
 
 
-	/** Change note properties.
+	/** PropertyChange note properties.
 	 * More efficient than DeltaCommand and has the important property that
 	 * it leaves the objects in the MidiModel (Notes) the same, thus
 	 * enabling selection and other state to persist across command
diff --git a/libs/ardour/ardour/midi_playlist.h b/libs/ardour/ardour/midi_playlist.h
index 32196206e2..46aea9f0b4 100644
--- a/libs/ardour/ardour/midi_playlist.h
+++ b/libs/ardour/ardour/midi_playlist.h
@@ -74,7 +74,7 @@ protected:
 private:
 	void dump () const;
 
-	bool region_changed (PBD::Change, boost::shared_ptr<Region>);
+	bool region_changed (PBD::PropertyChange, boost::shared_ptr<Region>);
 
 	NoteMode _note_mode;
 
diff --git a/libs/ardour/ardour/midi_region.h b/libs/ardour/ardour/midi_region.h
index 7309058b8e..d892e5837f 100644
--- a/libs/ardour/ardour/midi_region.h
+++ b/libs/ardour/ardour/midi_region.h
@@ -53,29 +53,29 @@ class MidiRegion : public Region
 	boost::shared_ptr<MidiSource> midi_source (uint32_t n=0) const;
 
 	/* Stub Readable interface */
-	virtual nframes_t read (Sample*, sframes_t /*pos*/, nframes_t /*cnt*/, int /*channel*/) const { return 0; }
-	virtual sframes_t readable_length() const { return length(); }
-
-	nframes_t read_at (Evoral::EventSink<nframes_t>& dst,
-			   sframes_t position,
-			   nframes_t dur,
-			   uint32_t  chan_n = 0,
-			   NoteMode  mode = Sustained,
-			   MidiStateTracker* tracker = 0) const;
-
-	nframes_t master_read_at (MidiRingBuffer<nframes_t>& dst,
-			sframes_t position,
-			nframes_t dur,
-			uint32_t  chan_n = 0,
-			NoteMode  mode = Sustained) const;
+	virtual framecnt_t read (Sample*, framepos_t /*pos*/, framecnt_t /*cnt*/, int /*channel*/) const { return 0; }
+	virtual framecnt_t readable_length() const { return length(); }
+
+	framecnt_t read_at (Evoral::EventSink<nframes_t>& dst,
+			    framepos_t position,
+			    framecnt_t dur,
+			    uint32_t  chan_n = 0,
+			    NoteMode  mode = Sustained,
+			    MidiStateTracker* tracker = 0) const;
+	
+	framepos_t master_read_at (MidiRingBuffer<nframes_t>& dst,
+				   framepos_t position,
+				   framecnt_t dur,
+				   uint32_t  chan_n = 0,
+				   NoteMode  mode = Sustained) const;
 
 	XMLNode& state (bool);
 	int      set_state (const XMLNode&, int version);
-
+	
 	int separate_by_channel (ARDOUR::Session&, std::vector< boost::shared_ptr<Region> >&) const;
 
 	/* automation */
-
+	
 	boost::shared_ptr<Evoral::Control>
 	control(const Evoral::Parameter& id, bool create=false) {
 		return model()->control(id, create);
@@ -96,32 +96,26 @@ class MidiRegion : public Region
   private:
 	friend class RegionFactory;
 
-	MidiRegion (boost::shared_ptr<MidiSource>, nframes_t start, nframes_t length);
-	MidiRegion (boost::shared_ptr<MidiSource>, nframes_t start, nframes_t length, const string& name, layer_t = 0, Region::Flag flags = Region::DefaultFlags);
-	MidiRegion (const SourceList &, nframes_t start, nframes_t length, const string& name, layer_t = 0, Region::Flag flags = Region::DefaultFlags);
-	MidiRegion (boost::shared_ptr<const MidiRegion>, nframes_t start, nframes_t length, const string& name, layer_t = 0, Region::Flag flags = Region::DefaultFlags);
-	MidiRegion (boost::shared_ptr<const MidiRegion>);
+	MidiRegion (boost::shared_ptr<MidiSource>);
+	MidiRegion (const SourceList&);
+	MidiRegion (boost::shared_ptr<const MidiRegion>, frameoffset_t offset = 0, bool offset_relative = true);
 	MidiRegion (boost::shared_ptr<MidiSource>, const XMLNode&);
 	MidiRegion (const SourceList &, const XMLNode&);
 
   private:
-	nframes_t _read_at (const SourceList&, Evoral::EventSink<nframes_t>& dst,
-			    sframes_t position,
-			    nframes_t dur,
-			    uint32_t chan_n = 0,
-			    NoteMode mode = Sustained, 
-			    MidiStateTracker* tracker = 0) const;
+	framecnt_t _read_at (const SourceList&, Evoral::EventSink<nframes_t>& dst,
+			     framepos_t position,
+			     framecnt_t dur,
+			     uint32_t chan_n = 0,
+			     NoteMode mode = Sustained, 
+			     MidiStateTracker* tracker = 0) const;
 
 	void recompute_at_start ();
 	void recompute_at_end ();
 
-	void set_position_internal (nframes_t pos, bool allow_bbt_recompute);
+	void set_position_internal (framepos_t pos, bool allow_bbt_recompute);
 
 	void switch_source(boost::shared_ptr<Source> source);
-
-  protected:
-
-	int set_live_state (const XMLNode&, int version, PBD::Change&, bool send);
 };
 
 } /* namespace ARDOUR */
diff --git a/libs/ardour/ardour/playlist.h b/libs/ardour/ardour/playlist.h
index 404fc61d2d..9cd02dec1e 100644
--- a/libs/ardour/ardour/playlist.h
+++ b/libs/ardour/ardour/playlist.h
@@ -58,7 +58,7 @@ class Playlist : public SessionObject
 	Playlist (Session&, const XMLNode&, DataType type, bool hidden = false);
 	Playlist (Session&, std::string name, DataType type, bool hidden = false);
 	Playlist (boost::shared_ptr<const Playlist>, std::string name, bool hidden = false);
-	Playlist (boost::shared_ptr<const Playlist>, nframes_t start, nframes_t cnt, std::string name, bool hidden = false);
+	Playlist (boost::shared_ptr<const Playlist>, framepos_t start, framecnt_t cnt, std::string name, bool hidden = false);
 
 	virtual ~Playlist ();
 
@@ -81,7 +81,7 @@ class Playlist : public SessionObject
 	bool hidden() const { return _hidden; }
 	bool empty() const;
 	uint32_t n_regions() const;
-	nframes_t get_maximum_extent () const;
+	framecnt_t get_maximum_extent () const;
 	layer_t top_layer() const;
 
 	EditMode get_edit_mode() const { return _edit_mode; }
@@ -89,39 +89,39 @@ class Playlist : public SessionObject
 
 	/* Editing operations */
 
-	void add_region (boost::shared_ptr<Region>, nframes_t position, float times = 1, bool auto_partition = false);
+	void add_region (boost::shared_ptr<Region>, framepos_t position, float times = 1, bool auto_partition = false);
 	void remove_region (boost::shared_ptr<Region>);
 	void get_equivalent_regions (boost::shared_ptr<Region>, std::vector<boost::shared_ptr<Region> >&);
 	void get_region_list_equivalent_regions (boost::shared_ptr<Region>, std::vector<boost::shared_ptr<Region> >&);
-	void replace_region (boost::shared_ptr<Region> old, boost::shared_ptr<Region> newr, nframes_t pos);
-	void split_region (boost::shared_ptr<Region>, nframes_t position);
-	void split (nframes64_t at);
-	void shift (nframes64_t at, nframes64_t distance, bool move_intersected, bool ignore_music_glue);
-	void partition (nframes_t start, nframes_t end, bool cut = false);
-	void duplicate (boost::shared_ptr<Region>, nframes_t position, float times);
-	void nudge_after (nframes_t start, nframes_t distance, bool forwards);
+	void replace_region (boost::shared_ptr<Region> old, boost::shared_ptr<Region> newr, framepos_t pos);
+	void split_region (boost::shared_ptr<Region>, framepos_t position);
+	void split (framepos_t at);
+	void shift (framepos_t at, frameoffset_t distance, bool move_intersected, bool ignore_music_glue);
+	void partition (framepos_t start, framepos_t end, bool cut = false);
+	void duplicate (boost::shared_ptr<Region>, framepos_t position, float times);
+	void nudge_after (framepos_t start, framecnt_t distance, bool forwards);
 	void shuffle (boost::shared_ptr<Region>, int dir);
 	void update_after_tempo_map_change ();
 
 	boost::shared_ptr<Playlist> cut  (std::list<AudioRange>&, bool result_is_hidden = true);
 	boost::shared_ptr<Playlist> copy (std::list<AudioRange>&, bool result_is_hidden = true);
-	int                         paste (boost::shared_ptr<Playlist>, nframes_t position, float times);
+	int                         paste (boost::shared_ptr<Playlist>, framepos_t position, float times);
 
 	const RegionList& region_list () const { return regions; }
 
-	RegionList*                regions_at (nframes_t frame);
-	RegionList*                regions_touched (nframes_t start, nframes_t end);
-	RegionList*                regions_to_read (nframes_t start, nframes_t end);
+	RegionList*                regions_at (framepos_t frame);
+	RegionList*                regions_touched (framepos_t start, framepos_t end);
+	RegionList*                regions_to_read (framepos_t start, framepos_t end);
 	boost::shared_ptr<Region>  find_region (const PBD::ID&) const;
-	boost::shared_ptr<Region>  top_region_at (nframes_t frame);
-	boost::shared_ptr<Region>  top_unmuted_region_at (nframes_t frame);
-	boost::shared_ptr<Region>  find_next_region (nframes_t frame, RegionPoint point, int dir);
-	nframes64_t                find_next_region_boundary (nframes64_t frame, int dir);
+	boost::shared_ptr<Region>  top_region_at (framepos_t frame);
+	boost::shared_ptr<Region>  top_unmuted_region_at (framepos_t frame);
+	boost::shared_ptr<Region>  find_next_region (framepos_t frame, RegionPoint point, int dir);
+	framepos_t                 find_next_region_boundary (framepos_t frame, int dir);
 	bool                       region_is_shuffle_constrained (boost::shared_ptr<Region>);
-	bool                       has_region_at (nframes64_t const) const;
+	bool                       has_region_at (framepos_t const) const;
 
 
-	nframes64_t find_next_transient (nframes64_t position, int dir);
+	framepos_t find_next_transient (framepos_t position, int dir);
 
 	void foreach_region (boost::function<void (boost::shared_ptr<Region>)>);
 
@@ -136,7 +136,7 @@ class Playlist : public SessionObject
 	PBD::Signal0<void>      NameChanged;
 	PBD::Signal0<void>      LengthChanged;
 	PBD::Signal0<void>      LayeringChanged;
-	PBD::Signal1<void,std::list< Evoral::RangeMove<nframes_t> > const &> RangesMoved;
+	PBD::Signal1<void,std::list< Evoral::RangeMove<framepos_t> > const &> RangesMoved;
 
 	static std::string bump_name (std::string old_name, Session&);
 
@@ -205,7 +205,7 @@ class Playlist : public SessionObject
 	bool             pending_contents_change;
 	bool             pending_layering;
 	bool             pending_length;
-	std::list< Evoral::RangeMove<nframes_t> > pending_range_moves;
+	std::list< Evoral::RangeMove<framepos_t> > pending_range_moves;
 	bool             save_on_thaw;
 	std::string      last_save_reason;
 	uint32_t         in_set_state;
@@ -223,7 +223,7 @@ class Playlist : public SessionObject
 	uint32_t        _read_data_count;
 	PBD::ID         _orig_diskstream_id;
 	uint64_t         layer_op_counter;
-	nframes_t        freeze_length;
+	framecnt_t       freeze_length;
 	bool             auto_partition;
 
 	/** true if relayering should be done using region's current layers and their `pending explicit relayer'
@@ -249,25 +249,25 @@ class Playlist : public SessionObject
 	void notify_length_changed ();
 	void notify_layering_changed ();
 	void notify_contents_changed ();
-	void notify_state_changed (PBD::Change);
+	void notify_state_changed (PBD::PropertyChange);
 	void notify_region_moved (boost::shared_ptr<Region>);
 
 	void mark_session_dirty();
 
-	void region_changed_proxy (PBD::Change, boost::weak_ptr<Region>);
-	virtual bool region_changed (PBD::Change, boost::shared_ptr<Region>);
+	void region_changed_proxy (PBD::PropertyChange, boost::weak_ptr<Region>);
+	virtual bool region_changed (PBD::PropertyChange, boost::shared_ptr<Region>);
 
-	void region_bounds_changed (PBD::Change, boost::shared_ptr<Region>);
+	void region_bounds_changed (PBD::PropertyChange, boost::shared_ptr<Region>);
 	void region_deleted (boost::shared_ptr<Region>);
 
 	void sort_regions ();
 
-	void possibly_splice (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude = boost::shared_ptr<Region>());
-	void possibly_splice_unlocked(nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude = boost::shared_ptr<Region>());
+	void possibly_splice (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude = boost::shared_ptr<Region>());
+	void possibly_splice_unlocked(framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude = boost::shared_ptr<Region>());
 
-	void core_splice (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude);
-	void splice_locked (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude);
-	void splice_unlocked (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude);
+	void core_splice (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude);
+	void splice_locked (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude);
+	void splice_unlocked (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude);
 
 	virtual void finalize_split_region (boost::shared_ptr<Region> /*original*/, boost::shared_ptr<Region> /*left*/, boost::shared_ptr<Region> /*right*/) {}
 
@@ -279,19 +279,19 @@ class Playlist : public SessionObject
 
 	boost::shared_ptr<Region> region_by_id (PBD::ID);
 
-	bool add_region_internal (boost::shared_ptr<Region>, nframes_t position);
+	bool add_region_internal (boost::shared_ptr<Region>, framepos_t position);
 
 	int remove_region_internal (boost::shared_ptr<Region>);
-	RegionList *find_regions_at (nframes_t frame);
+	RegionList *find_regions_at (framepos_t frame);
 	void copy_regions (RegionList&) const;
-	void partition_internal (nframes_t start, nframes_t end, bool cutting, RegionList& thawlist);
+	void partition_internal (framepos_t start, framepos_t end, bool cutting, RegionList& thawlist);
 
-	nframes_t _get_maximum_extent() const;
+	framecnt_t _get_maximum_extent() const;
 
-	boost::shared_ptr<Playlist> cut_copy (boost::shared_ptr<Playlist> (Playlist::*pmf)(nframes_t, nframes_t, bool),
-			std::list<AudioRange>& ranges, bool result_is_hidden);
-	boost::shared_ptr<Playlist> cut (nframes_t start, nframes_t cnt, bool result_is_hidden);
-	boost::shared_ptr<Playlist> copy (nframes_t start, nframes_t cnt, bool result_is_hidden);
+	boost::shared_ptr<Playlist> cut_copy (boost::shared_ptr<Playlist> (Playlist::*pmf)(framepos_t, framecnt_t, bool),
+					      std::list<AudioRange>& ranges, bool result_is_hidden);
+	boost::shared_ptr<Playlist> cut (framepos_t start, framecnt_t cnt, bool result_is_hidden);
+	boost::shared_ptr<Playlist> copy (framepos_t start, framecnt_t cnt, bool result_is_hidden);
 
 	int move_region_to_layer (layer_t, boost::shared_ptr<Region> r, int dir);
 	void relayer ();
@@ -301,7 +301,7 @@ class Playlist : public SessionObject
 
 	void timestamp_layer_op (boost::shared_ptr<Region>);
 
-	void _split_region (boost::shared_ptr<Region>, nframes_t position);
+	void _split_region (boost::shared_ptr<Region>, framepos_t position);
 };
 
 } /* namespace ARDOUR */
diff --git a/libs/ardour/ardour/readable.h b/libs/ardour/ardour/readable.h
index 1ca6a7dbb2..d927cbe4af 100644
--- a/libs/ardour/ardour/readable.h
+++ b/libs/ardour/ardour/readable.h
@@ -10,8 +10,8 @@ class Readable {
 	Readable () {}
 	virtual ~Readable() {}
 
-	virtual nframes_t read (Sample*, sframes_t pos, nframes_t cnt, int channel) const = 0;
-	virtual sframes_t readable_length() const = 0;
+	virtual framecnt_t read (Sample*, framepos_t pos, framecnt_t cnt, int channel) const = 0;
+	virtual framecnt_t readable_length() const = 0;
 	virtual uint32_t  n_channels () const = 0;
 };
 
diff --git a/libs/ardour/ardour/region.h b/libs/ardour/ardour/region.h
index 9c78285a09..60ccf66984 100644
--- a/libs/ardour/ardour/region.h
+++ b/libs/ardour/ardour/region.h
@@ -36,8 +36,33 @@
 
 class XMLNode;
 
+
 namespace ARDOUR {
 
+namespace Properties {
+	extern PBD::PropertyDescriptor<bool> muted;
+	extern PBD::PropertyDescriptor<bool> opaque;
+	extern PBD::PropertyDescriptor<bool> locked;
+	extern PBD::PropertyDescriptor<bool> automatic;
+	extern PBD::PropertyDescriptor<bool> whole_file;
+	extern PBD::PropertyDescriptor<bool> import;
+	extern PBD::PropertyDescriptor<bool> external;
+	extern PBD::PropertyDescriptor<bool> sync_marked;
+	extern PBD::PropertyDescriptor<bool> left_of_split;
+	extern PBD::PropertyDescriptor<bool> right_of_split;
+	extern PBD::PropertyDescriptor<bool> hidden;
+	extern PBD::PropertyDescriptor<bool> position_locked;
+	extern PBD::PropertyDescriptor<framepos_t> start;
+	extern PBD::PropertyDescriptor<framecnt_t> length;
+	extern PBD::PropertyDescriptor<framepos_t> position;
+	extern PBD::PropertyDescriptor<framecnt_t> sync_position;
+	extern PBD::PropertyDescriptor<layer_t> layer;
+	extern PBD::PropertyDescriptor<framepos_t> ancestral_start;
+	extern PBD::PropertyDescriptor<framecnt_t> ancestral_length;
+	extern PBD::PropertyDescriptor<float> stretch;
+	extern PBD::PropertyDescriptor<float> shift;
+};
+
 class Playlist;
 class Filter;
 class ExportSpecification;
@@ -48,6 +73,7 @@ enum RegionEditState {
 	EditChangesID      = 2
 };
 
+
 class Region
 	: public SessionObject
 	, public boost::enable_shared_from_this<Region>
@@ -56,106 +82,82 @@ class Region
   public:
 	typedef std::vector<boost::shared_ptr<Source> > SourceList;
 
-	enum Flag {
-		Muted = 0x1,
-		Opaque = 0x2,
-		EnvelopeActive = 0x4,
-		DefaultFadeIn = 0x8,
-		DefaultFadeOut = 0x10,
-		Locked = 0x20,
-		Automatic = 0x40,
-		WholeFile = 0x80,
-		FadeIn = 0x100,
-		FadeOut = 0x200,
-		Copied = 0x400,
-		Import = 0x800,
-		External = 0x1000,
-		SyncMarked = 0x2000,
-		LeftOfSplit = 0x4000,
-		RightOfSplit = 0x8000,
-		Hidden = 0x10000,
-		DoNotSendPropertyChanges = 0x20000,
-		PositionLocked = 0x40000,
-		//
-		range_guarantoor = USHRT_MAX
-	};
-
+	static void make_property_quarks ();
+	
 	enum PositionLockStyle {
 		AudioTime,
 		MusicTime
 	};
 
-	static const Flag DefaultFlags = Flag (Opaque|DefaultFadeIn|DefaultFadeOut|FadeIn|FadeOut);
-
-	static PBD::Change FadeChanged;
-	static PBD::Change SyncOffsetChanged;
-	static PBD::Change MuteChanged;
-	static PBD::Change OpacityChanged;
-	static PBD::Change LockChanged;
-	static PBD::Change LayerChanged;
-	static PBD::Change HiddenChanged;
+	static PBD::PropertyChange FadeChanged;
+	static PBD::PropertyChange SyncOffsetChanged;
+	static PBD::PropertyChange MuteChanged;
+	static PBD::PropertyChange OpacityChanged;
+	static PBD::PropertyChange LockChanged;
+	static PBD::PropertyChange LayerChanged;
+	static PBD::PropertyChange HiddenChanged;
 
-	PBD::Signal1<void,PBD::Change> StateChanged;
+	PBD::Signal1<void,PBD::PropertyChange> StateChanged;
 	static PBD::Signal1<void,boost::shared_ptr<ARDOUR::Region> > RegionPropertyChanged;
-	void unlock_property_changes () { _flags = Flag (_flags & ~DoNotSendPropertyChanges); }
-	void block_property_changes () { _flags = Flag (_flags | DoNotSendPropertyChanges); }
 
+	void unlock_property_changes () { _no_property_changes = false; }
+	void block_property_changes () { _no_property_changes = true; }
+	
 	virtual ~Region();
-
+	
 	/** Note: changing the name of a Region does not constitute an edit */
 	bool set_name (const std::string& str);
 
 	const DataType& data_type() const { return _type; }
 
 	/** How the region parameters play together:
-	 * <PRE>
-	 * |------------------------------------------------------------------- track
-	 *                    |..........[------------------].....| region
-	 * |-----------------------------| _position
-	 *                               |------------------| _length
-	 *                    |----------| _start
-	 * </PRE>
+	 *   
+	 * POSITION: first frame of the region along the timeline
+	 * START:    first frame of the region within its source(s)
+	 * LENGTH:   number of frames the region represents
 	 */
-	nframes_t position () const { return _position; }
-	nframes_t start ()    const { return _start; }
-	nframes_t length()    const { return _length; }
-	layer_t   layer ()    const { return _layer; }
+	sframes_t  position () const { return _position; }
+	sframes_t  start ()    const { return _start; }
+	framecnt_t length()    const { return _length; }
+	layer_t    layer ()    const { return _layer; }
 
-	sframes_t source_length(uint32_t n) const;
+	framecnt_t source_length(uint32_t n) const;
 
 	/* these two are valid ONLY during a StateChanged signal handler */
 
-	nframes_t last_position() const { return _last_position; }
-	nframes_t last_length() const { return _last_length; }
+	sframes_t  last_position() const { return _last_position; }
+	framecnt_t last_length() const { return _last_length; }
 
-	nframes64_t ancestral_start () const { return _ancestral_start; }
-	nframes64_t ancestral_length () const { return _ancestral_length; }
+	sframes_t ancestral_start () const { return _ancestral_start; }
+	framecnt_t ancestral_length () const { return _ancestral_length; }
 	float stretch() const { return _stretch; }
 	float shift() const { return _shift; }
 
 	void set_ancestral_data (nframes64_t start, nframes64_t length, float stretch, float shift);
 
-	nframes_t sync_offset(int& dir) const;
-	nframes_t sync_position() const;
-	nframes_t sync_point () const;
-
-	nframes_t adjust_to_sync (nframes_t) const;
+	frameoffset_t sync_offset(int& dir) const;
+	framepos_t sync_position() const;
+	framepos_t sync_point () const;
+	
+	framepos_t adjust_to_sync (framepos_t) const;
 
 	/* first_frame() is an alias; last_frame() just hides some math */
 
-	nframes_t first_frame() const { return _position; }
-	nframes_t last_frame() const { return _position + _length - 1; }
-
-	Flag flags()      const { return _flags; }
-	bool hidden()     const { return _flags & Hidden; }
-	bool muted()      const { return _flags & Muted; }
-	bool opaque ()    const { return _flags & Opaque; }
-	bool locked()     const { return _flags & Locked; }
-	bool position_locked() const { return _flags & PositionLocked; }
-	bool automatic()  const { return _flags & Automatic; }
-	bool whole_file() const { return _flags & WholeFile ; }
-	bool captured()   const { return !(_flags & (Region::Flag (Region::Import|Region::External))); }
-	bool can_move()   const { return !(_flags & (Locked|PositionLocked)); }
+	framepos_t first_frame() const { return _position; }
+	framepos_t last_frame()  const { return _position + _length - 1; }
+
+	bool hidden()     const  { return _hidden; }
+	bool muted()      const  { return _muted; }
+	bool opaque ()    const  { return _opaque; }
+	bool locked()     const  { return _locked; }
+	bool position_locked() const { return _position_locked; }
+	bool automatic()  const  { return _automatic; }
+	bool whole_file() const  { return _whole_file; }
+	bool captured()   const  { return !(_import || _external); }
+	bool can_move()   const  { return !_position_locked; }
+	bool sync_marked() const { return _sync_marked; }
+	bool external() const    { return _external; }
+	bool import() const      { return _import; }
 
 	PositionLockStyle positional_lock_style() const { return _positional_lock_style; }
 	void set_position_lock_style (PositionLockStyle ps);
@@ -164,11 +166,11 @@ class Region
 	void freeze ();
 	void thaw ();
 
-	bool covers (nframes_t frame) const {
+	bool covers (framepos_t frame) const {
 		return first_frame() <= frame && frame <= last_frame();
 	}
 
-	OverlapType coverage (nframes_t start, nframes_t end) const {
+	OverlapType coverage (framepos_t start, framepos_t end) const {
 		return ARDOUR::coverage (first_frame(), last_frame(), start, end);
 	}
 
@@ -181,21 +183,21 @@ class Region
 
 	/* EDITING OPERATIONS */
 
-	void set_length (nframes_t, void *src);
-	void set_start (nframes_t, void *src);
-	void set_position (nframes_t, void *src);
-	void set_position_on_top (nframes_t, void *src);
-	void special_set_position (nframes_t);
+	void set_length (framecnt_t, void *src);
+	void set_start (framepos_t, void *src);
+	void set_position (framepos_t, void *src);
+	void set_position_on_top (framepos_t, void *src);
+	void special_set_position (framepos_t);
 	void update_position_after_tempo_map_change ();
-	void nudge_position (nframes64_t, void *src);
+	void nudge_position (frameoffset_t, void *src);
 
 	bool at_natural_position () const;
 	void move_to_natural_position (void *src);
 
-	void trim_start (nframes_t new_position, void *src);
-	void trim_front (nframes_t new_position, void *src);
-	void trim_end (nframes_t new_position, void *src);
-	void trim_to (nframes_t position, nframes_t length, void *src);
+	void trim_start (framepos_t new_position, void *src);
+	void trim_front (framepos_t new_position, void *src);
+	void trim_end (framepos_t new_position, void *src);
+	void trim_to (framepos_t position, framecnt_t length, void *src);
 
 	void set_layer (layer_t l); /* ONLY Playlist can call this */
 	void raise ();
@@ -203,17 +205,19 @@ class Region
 	void raise_to_top ();
 	void lower_to_bottom ();
 
-	void set_sync_position (nframes_t n);
+	void set_sync_position (framepos_t n);
 	void clear_sync_position ();
 	void set_hidden (bool yn);
 	void set_muted (bool yn);
+	void set_whole_file (bool yn);
+	void set_automatic (bool yn);
 	void set_opaque (bool yn);
 	void set_locked (bool yn);
 	void set_position_locked (bool yn);
 
 	int apply (Filter&);
 
-	virtual uint32_t read_data_count() const { return _read_data_count; }
+	virtual uint64_t read_data_count() const { return _read_data_count; }
 
 	boost::shared_ptr<ARDOUR::Playlist> playlist() const { return _playlist.lock(); }
 	virtual void set_playlist (boost::weak_ptr<ARDOUR::Playlist>);
@@ -242,7 +246,6 @@ class Region
 	XMLNode&         get_state ();
 	virtual XMLNode& state (bool);
 	virtual int      set_state (const XMLNode&, int version);
-	virtual int      set_live_state (const XMLNode&, int version, PBD::Change&, bool send);
 
 	virtual boost::shared_ptr<Region> get_parent() const;
 
@@ -278,62 +281,77 @@ class Region
   protected:
 	friend class RegionFactory;
 
-	Region (boost::shared_ptr<Source> src, nframes_t start, nframes_t length,
-		const std::string& name, DataType type, layer_t = 0, Flag flags = DefaultFlags);
-	Region (const SourceList& srcs, nframes_t start, nframes_t length,
-		const std::string& name, DataType type, layer_t = 0, Flag flags = DefaultFlags);
-
-	Region (boost::shared_ptr<const Region>, nframes_t start, nframes_t length, const std::string& name, layer_t = 0, Flag flags = DefaultFlags);
-	Region (boost::shared_ptr<const Region>, nframes_t length, const std::string& name, layer_t = 0, Flag flags = DefaultFlags);
+	/** Construct a region from a single source */
+	Region (boost::shared_ptr<Source> src);
+	/** Construct a region from multiple sources*/
+	Region (const SourceList& srcs);
+	/** Construct a region from another region, at an offset within that region */
+	Region (boost::shared_ptr<const Region>, frameoffset_t start_offset = 0, bool start_relative = true);
+	/** Construct a region as a copy of another region, but with different sources */
+	Region (boost::shared_ptr<const Region>, const SourceList&);
+	/** normal Region copy constructor */
 	Region (boost::shared_ptr<const Region>);
+
+	/** Construct a region from 1 source and XML state */
 	Region (boost::shared_ptr<Source> src, const XMLNode&);
+	/** Construct a region from multiple sources and XML state */
 	Region (const SourceList& srcs, const XMLNode&);
 
-	Region (Session& s, nframes_t start, nframes_t length, const std::string& name, DataType, layer_t = 0, Flag flags = DefaultFlags);
+	/** Constructor for derived types only */
+	Region (Session& s, framepos_t start, framecnt_t length, const std::string& name, DataType);
 
   protected:
-	void copy_stuff (boost::shared_ptr<const Region>, nframes_t start, nframes_t length, const std::string& name, layer_t, Flag flags);
-
-	XMLNode& get_short_state (); /* used only by Session */
-
-	void send_change (PBD::Change);
+	void send_change (PBD::PropertyChange);
 
-	void trim_to_internal (nframes_t position, nframes_t length, void *src);
-	virtual void set_position_internal (nframes_t pos, bool allow_bbt_recompute);
+	void trim_to_internal (framepos_t position, framecnt_t length, void *src);
+	virtual void set_position_internal (framepos_t pos, bool allow_bbt_recompute);
 
-	bool copied() const { return _flags & Copied; }
 	void maybe_uncopy ();
 	void first_edit ();
 
-	bool verify_start (nframes_t);
-	bool verify_start_and_length (nframes_t, nframes_t&);
-	bool verify_start_mutable (nframes_t&_start);
-	bool verify_length (nframes_t);
+	bool verify_start (framepos_t);
+	bool verify_start_and_length (framepos_t, framecnt_t&);
+	bool verify_start_mutable (framepos_t&_start);
+	bool verify_length (framecnt_t);
 
 	virtual void recompute_at_start () = 0;
 	virtual void recompute_at_end () = 0;
-
+	
 	DataType                _type;
-	PBD::EnumState<Flag>    _flags;
-	PBD::State<nframes_t>   _start;
-	PBD::State<nframes_t>   _length;
-	nframes_t               _last_length;
-	PBD::State<nframes_t>   _position;
-	nframes_t               _last_position;
+	bool                    _no_property_changes;
+
+	PBD::Property<bool>        _muted;
+	PBD::Property<bool>        _opaque;
+	PBD::Property<bool>        _locked;
+	PBD::Property<bool>        _automatic;
+	PBD::Property<bool>        _whole_file;
+	PBD::Property<bool>        _import;
+	PBD::Property<bool>        _external;
+	PBD::Property<bool>        _sync_marked;
+	PBD::Property<bool>        _left_of_split;
+	PBD::Property<bool>        _right_of_split;
+	PBD::Property<bool>        _hidden;
+	PBD::Property<bool>        _position_locked;
+	PBD::Property<framepos_t>  _start;
+	PBD::Property<framecnt_t>  _length;
+	PBD::Property<framepos_t>  _position;
+	PBD::Property<framepos_t>  _sync_position;
+	PBD::Property<layer_t>     _layer;
+	PBD::Property<framepos_t>  _ancestral_start;
+	PBD::Property<framecnt_t>  _ancestral_length;
+	PBD::Property<float>       _stretch;
+	PBD::Property<float>       _shift;
+
+	framecnt_t              _last_length;
+	framepos_t              _last_position;
 	PositionLockStyle       _positional_lock_style;
-	PBD::State<nframes_t>   _sync_position;
-	PBD::State<layer_t>     _layer;
 	mutable RegionEditState _first_edit;
 	int                     _frozen;
-	PBD::State<nframes64_t> _ancestral_start;
-	PBD::State<nframes64_t> _ancestral_length;
-	PBD::State<float>       _stretch;
-	PBD::State<float>       _shift;
 	BBT_Time                _bbt_time;
 	AnalysisFeatureList     _transients;
 	bool                    _valid_transients;
-	mutable uint32_t        _read_data_count;  ///< modified in read()
-	PBD::Change             _pending_changed;
+	mutable uint64_t        _read_data_count;  ///< modified in read()
+	PBD::PropertyChange             _pending_changed;
 	uint64_t                _last_layer_op;  ///< timestamp
 	Glib::Mutex             _lock;
 	SourceList              _sources;
@@ -345,9 +363,12 @@ class Region
 
 	boost::weak_ptr<ARDOUR::Playlist> _playlist;
 
-private:
+	virtual int _set_state (const XMLNode&, int version, PBD::PropertyChange& what_changed, bool send_signal);
 
-	void register_states ();
+	PBD::PropertyChange set_property (const PBD::PropertyBase&);
+	void register_properties ();
+
+private:
 	void use_sources (SourceList const &);
 };
 
diff --git a/libs/ardour/ardour/region_factory.h b/libs/ardour/ardour/region_factory.h
index 64d3417287..16e48828d4 100644
--- a/libs/ardour/ardour/region_factory.h
+++ b/libs/ardour/ardour/region_factory.h
@@ -44,29 +44,35 @@ class RegionFactory {
 	/** This is emitted only when a new id is assigned. Therefore,
 	   in a pure Region copy, it will not be emitted.
 
-	   It must be emitted by derived classes, not Region
+	   It must be emitted using a derived instance of Region, not Region
 	   itself, to permit dynamic_cast<> to be used to
 	   infer the type of Region.
 	*/
 	static PBD::Signal1<void,boost::shared_ptr<Region> >  CheckNewRegion;
 
-	static boost::shared_ptr<Region> create (boost::shared_ptr<const Region>);
-
-	/* note: both of the first two should use const shared_ptr as well, but
-	   gcc 4.1 doesn't seem to be able to disambiguate them if they do.
-	*/
-
-	static boost::shared_ptr<Region> create (boost::shared_ptr<Region>, nframes_t start,
-			nframes_t length, const std::string& name,
-			layer_t = 0, Region::Flag flags = Region::DefaultFlags, bool announce = true);
-	static boost::shared_ptr<Region> create (boost::shared_ptr<AudioRegion>, nframes_t start,
-			nframes_t length, const std::string& name,
-			layer_t = 0, Region::Flag flags = Region::DefaultFlags, bool announce = true);
-	static boost::shared_ptr<Region> create (boost::shared_ptr<Region>, const SourceList&, const std::string& name, layer_t = 0, Region::Flag flags = Region::DefaultFlags, bool announce = true);
-	static boost::shared_ptr<Region> create (boost::shared_ptr<Source>, nframes_t start, nframes_t length, const std::string& name, layer_t = 0, Region::Flag flags = Region::DefaultFlags, bool announce = true);
-	static boost::shared_ptr<Region> create (const SourceList &, nframes_t start, nframes_t length, const std::string& name, layer_t = 0, Region::Flag flags = Region::DefaultFlags, bool announce = true);
+	/** create a "pure copy" of Region @param other */
+	static boost::shared_ptr<Region> create (boost::shared_ptr<const Region> other);
+
+	/** create a region from a single Source */
+	static boost::shared_ptr<Region> create (boost::shared_ptr<Source>, 
+						 const PBD::PropertyList&, bool announce = true);
+	/** create a region from a multiple sources */
+	static boost::shared_ptr<Region> create (const SourceList &, 
+						 const PBD::PropertyList&, bool announce = true);
+	/** create a copy of @other starting at zero within @param other's sources */
+	static boost::shared_ptr<Region> create (boost::shared_ptr<Region> other, 
+						 const PBD::PropertyList&, bool announce = true);
+	/** create a copy of @other starting at @param offset within @param other */
+	static boost::shared_ptr<Region> create (boost::shared_ptr<Region>, frameoffset_t offset, 
+						 const PBD::PropertyList&, bool announce = true);
+	/** create a "copy" of @param other but using a different set of sources @param srcs */
+	static boost::shared_ptr<Region> create (boost::shared_ptr<Region> other, const SourceList& srcs, 
+						 const PBD::PropertyList&, bool announce = true);
+	
+	/** create a region with no sources, using XML state */
 	static boost::shared_ptr<Region> create (Session&, XMLNode&, bool);
-	static boost::shared_ptr<Region> create (SourceList &, const XMLNode&);
+	/** create a region with specified sources @param srcs and XML state */
+	static boost::shared_ptr<Region> create (SourceList& srcs, const XMLNode&);
 
   private:
 	static std::map<PBD::ID,boost::weak_ptr<Region> > region_map;
diff --git a/libs/ardour/ardour/route_group.h b/libs/ardour/ardour/route_group.h
index 48b5cb52db..820295b54a 100644
--- a/libs/ardour/ardour/route_group.h
+++ b/libs/ardour/ardour/route_group.h
@@ -24,46 +24,52 @@
 #include <set>
 #include <string>
 #include <stdint.h>
-#include "pbd/signals.h"
 
+#include "pbd/signals.h"
 #include "pbd/stateful.h"
 #include "pbd/signals.h"
 
 #include "ardour/types.h"
+#include "ardour/session_object.h"
 
 namespace ARDOUR {
 
+namespace Properties {
+	extern PBD::PropertyDescriptor<bool> relative;
+	extern PBD::PropertyDescriptor<bool> active;
+	extern PBD::PropertyDescriptor<bool> gain;
+	extern PBD::PropertyDescriptor<bool> mute;
+	extern PBD::PropertyDescriptor<bool> solo;
+	extern PBD::PropertyDescriptor<bool> recenable;
+	extern PBD::PropertyDescriptor<bool> select;
+	extern PBD::PropertyDescriptor<bool> edit;
+	/* we use this, but its declared in region.cc */
+	extern PBD::PropertyDescriptor<bool> hidden;
+};
+
 class Route;
 class Track;
 class AudioTrack;
 class Session;
 
-class RouteGroup : public PBD::Stateful, public PBD::ScopedConnectionList {
-public:
-	enum Flag {
-		Relative = 0x1,
-		Active = 0x2,
-		Hidden = 0x4
-	};
-
-	enum Property {
-		Gain = 0x1,
-		Mute = 0x2,
-		Solo = 0x4,
-		RecEnable = 0x8,
-		Select = 0x10,
-		Edit = 0x20
-	};
-
-	RouteGroup (Session& s, const std::string &n, Flag f = Flag(0), Property p = Property(0));
+class RouteGroup : public SessionObject 
+{
+  public:
+	static void make_property_quarks();
+	
+	RouteGroup (Session& s, const std::string &n);
 	~RouteGroup ();
 
-	const std::string& name() { return _name; }
-	void set_name (std::string str);
+	bool is_active () const { return _active.val(); }
+	bool is_relative () const { return _relative.val(); }
+	bool is_hidden () const { return _hidden.val(); }
+	bool is_gain () const { return _gain.val(); }
+	bool is_mute () const { return _mute.val(); }
+	bool is_solo () const { return _solo.val(); }
+	bool is_recenable () const { return _recenable.val(); }
+	bool is_select () const { return _select.val(); }
+	bool is_edit () const { return _edit.val(); }
 
-	bool is_active () const { return _flags & Active; }
-	bool is_relative () const { return _flags & Relative; }
-	bool is_hidden () const { return _flags & Hidden; }
 	bool empty() const {return routes->empty();}
 	size_t size() const { return routes->size();}
 
@@ -74,20 +80,14 @@ public:
 	void set_relative (bool yn, void *src);
 	void set_hidden (bool yn, void *src);
 
-	bool property (Property p) const {
-		return ((_properties & p) == p);
-	}
-
-	bool active_property (Property p) const {
-		return is_active() && property (p);
-	}
+	void set_gain (bool yn);
+	void set_mute (bool yn);
+	void set_solo (bool yn);
+	void set_recenable (bool yn);
+	void set_select (bool yn);
+	void set_edit (bool yn);
 
-	void set_property (Property p, bool v) {
-		_properties = (Property) (_properties & ~p);
-		if (v) {
-			_properties = (Property) (_properties | p);
-		}
-	}
+	bool enabled_property (PBD::PropertyID);
 
 	int add (boost::shared_ptr<Route>);
 	int remove (boost::shared_ptr<Route>);
@@ -131,17 +131,26 @@ public:
 	PBD::Signal0<void> changed;
 	PBD::Signal1<void,void*> FlagsChanged;
 
+	static PBD::PropertyChange FlagsChange;
+	static PBD::PropertyChange PropertiesChange;
+
 	XMLNode& get_state ();
 	
 	int set_state (const XMLNode&, int version);
 	
 private:
-	Session& _session;
 	boost::shared_ptr<RouteList> routes;
 	boost::shared_ptr<Route> subgroup_bus;
-	std::string _name;
-	Flag _flags;
-	Property _properties;
+
+	PBD::Property<bool> _relative;
+	PBD::Property<bool> _active;
+	PBD::Property<bool> _hidden;
+	PBD::Property<bool> _gain;
+	PBD::Property<bool> _mute;
+	PBD::Property<bool> _solo;
+	PBD::Property<bool> _recenable;
+	PBD::Property<bool> _select;
+	PBD::Property<bool> _edit;
 
 	void remove_when_going_away (boost::weak_ptr<Route>);
 	int set_state_2X (const XMLNode&, int);
diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 06d5337b86..154c5d0078 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -1210,7 +1210,7 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 	void xrun_recovery ();
 
 	TempoMap    *_tempo_map;
-	void          tempo_map_changed (PBD::Change);
+	void          tempo_map_changed (PBD::PropertyChange);
 
 	/* edit/mix groups */
 
@@ -1257,7 +1257,7 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 	RegionList regions;
 
 	void add_region (boost::shared_ptr<Region>);
-	void region_changed (PBD::Change, boost::weak_ptr<Region>);
+	void region_changed (PBD::PropertyChange, boost::weak_ptr<Region>);
 	void remove_region (boost::weak_ptr<Region>);
 
 	int load_regions (const XMLNode& node);
diff --git a/libs/ardour/ardour/session_object.h b/libs/ardour/ardour/session_object.h
index 069badcb6a..1f81cf6fd2 100644
--- a/libs/ardour/ardour/session_object.h
+++ b/libs/ardour/ardour/session_object.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2000-2007 Paul Davis
+    Copyright (C) 2000-2010 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -24,12 +24,17 @@
 #include "pbd/statefuldestructible.h"
 #include "pbd/signals.h"
 
+#include "ardour/ardour.h"
 #include "ardour/session_handle.h"
 
 #include "i18n.h"
 
 namespace ARDOUR {
 
+namespace Properties {
+	extern PBD::PropertyDescriptor<std::string> name;
+}
+
 class Session;
 
 /** A named object associated with a Session. Objects derived from this class are
@@ -39,16 +44,20 @@ class Session;
 class SessionObject : public SessionHandleRef, public PBD::StatefulDestructible
 {
   public:
+	static void make_property_quarks ();
+
 	SessionObject (Session& session, const std::string& name)
 		: SessionHandleRef (session)
-		, _name (X_("name"), PBD::Change (0), name)
+		, _name (Properties::name, PBD::PropertyChange (0), name)
 	{
-		add_state (_name);
+		add_property (_name);
 	}
 	
 	Session&    session() const { return _session; }
 	std::string name()    const { return _name; }
 
+	PBD::PropertyChange set_property (const PBD::PropertyBase& prop);
+
 	virtual bool set_name (const std::string& str) {
 		if (_name != str) {
 			_name = str;
@@ -60,7 +69,7 @@ class SessionObject : public SessionHandleRef, public PBD::StatefulDestructible
 	PBD::Signal0<void> NameChanged;
 
   protected:
-	PBD::State<std::string> _name;
+	PBD::Property<std::string> _name;
 };
 
 } // namespace ARDOUR
diff --git a/libs/ardour/ardour/silentfilesource.h b/libs/ardour/ardour/silentfilesource.h
index ec7f1c4d0b..9b20f6f1b0 100644
--- a/libs/ardour/ardour/silentfilesource.h
+++ b/libs/ardour/ardour/silentfilesource.h
@@ -39,7 +39,7 @@ public:
 protected:
 	friend class SourceFactory;
 
-	SilentFileSource (Session& s, const XMLNode& x, nframes_t len, float srate)
+	SilentFileSource (Session& s, const XMLNode& x, framecnt_t len, float srate)
 		: Source (s, x)
 		, AudioFileSource (s, x, false)
 		, _sample_rate(srate)
@@ -47,17 +47,17 @@ protected:
 		_length = len;
 	}
 
-	nframes_t read_unlocked (Sample *dst, sframes_t /*start*/, nframes_t cnt) const {
+	framecnt_t read_unlocked (Sample *dst, framepos_t /*start*/, framecnt_t cnt) const {
 		memset (dst, 0, sizeof (Sample) * cnt);
 		return cnt;
 	}
 
-	nframes_t write_unlocked (Sample */*dst*/, nframes_t /*cnt*/) { return 0; }
-
+	framecnt_t write_unlocked (Sample */*dst*/, framecnt_t /*cnt*/) { return 0; }
+	
 	void set_header_timeline_position () {}
 
-	int read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t /*start*/, nframes_t /*cnt*/,
-	double /*samples_per_unit*/, nframes_t /*fpp*/) const {
+	int read_peaks_with_fpp (PeakData *peaks, framecnt_t npeaks, framepos_t /*start*/, framecnt_t /*cnt*/,
+				 double /*samples_per_unit*/, framecnt_t /*fpp*/) const {
 		memset (peaks, 0, sizeof (PeakData) * npeaks);
 		return 0;
 	}
diff --git a/libs/ardour/ardour/sndfilesource.h b/libs/ardour/ardour/sndfilesource.h
index 95829769f6..19dcb13536 100644
--- a/libs/ardour/ardour/sndfilesource.h
+++ b/libs/ardour/ardour/sndfilesource.h
@@ -65,10 +65,9 @@ class SndFileSource : public AudioFileSource {
   protected:
 	void set_header_timeline_position ();
 
-	nframes_t read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const;
-	nframes_t write_unlocked (Sample *dst, nframes_t cnt);
-
-	nframes_t write_float (Sample* data, sframes_t pos, nframes_t cnt);
+	framecnt_t read_unlocked (Sample *dst, framepos_t start, framecnt_t cnt) const;
+	framecnt_t write_unlocked (Sample *dst, framecnt_t cnt);
+	framecnt_t write_float (Sample* data, framepos_t pos, framecnt_t cnt);
 
   private:
 	SNDFILE *sf;
@@ -77,26 +76,26 @@ class SndFileSource : public AudioFileSource {
 
 	void init_sndfile ();
 	int open();
-	int setup_broadcast_info (sframes_t when, struct tm&, time_t);
+	int setup_broadcast_info (framepos_t when, struct tm&, time_t);
 
 	/* destructive */
 
-	static nframes_t xfade_frames;
+	static framecnt_t xfade_frames;
 	static gain_t* out_coefficient;
 	static gain_t* in_coefficient;
 
 	bool          _capture_start;
 	bool          _capture_end;
-	sframes_t      capture_start_frame;
-	sframes_t      file_pos; // unit is frames
-	nframes_t      xfade_out_count;
-	nframes_t      xfade_in_count;
+	framepos_t     capture_start_frame;
+	framepos_t     file_pos; // unit is frames
+	framecnt_t     xfade_out_count;
+	framecnt_t     xfade_in_count;
 	Sample*        xfade_buf;
-
-	nframes_t crossfade (Sample* data, nframes_t cnt, int dir);
-	void set_timeline_position (int64_t);
-	nframes_t destructive_write_unlocked (Sample *dst, nframes_t cnt);
-	nframes_t nondestructive_write_unlocked (Sample *dst, nframes_t cnt);
+	
+	framecnt_t crossfade (Sample* data, framecnt_t cnt, int dir);
+	void set_timeline_position (framepos_t);
+	framecnt_t destructive_write_unlocked (Sample *dst, framecnt_t cnt);
+	framecnt_t nondestructive_write_unlocked (Sample *dst, framecnt_t cnt);
 	void handle_header_position_change ();
 	PBD::ScopedConnection header_position_connection;
 };
diff --git a/libs/ardour/ardour/source.h b/libs/ardour/ardour/source.h
index b91d8f129c..83366bbb78 100644
--- a/libs/ardour/ardour/source.h
+++ b/libs/ardour/ardour/source.h
@@ -59,12 +59,12 @@ class Source : public SessionObject
 	time_t timestamp() const { return _timestamp; }
 	void stamp (time_t when) { _timestamp = when; }
 
-	virtual sframes_t length (sframes_t pos) const = 0;
-	virtual void      update_length (sframes_t pos, sframes_t cnt) = 0;
+	virtual framecnt_t length (framepos_t pos) const = 0;
+	virtual void       update_length (framepos_t pos, framecnt_t cnt) = 0;
 
 	virtual const Glib::ustring& path() const = 0;
 
-	virtual nframes64_t natural_position() const { return 0; }
+	virtual framepos_t natural_position() const { return 0; }
 
 	void mark_for_remove();
 
diff --git a/libs/ardour/ardour/tempo.h b/libs/ardour/ardour/tempo.h
index d85247bec4..5c2d3d6918 100644
--- a/libs/ardour/ardour/tempo.h
+++ b/libs/ardour/ardour/tempo.h
@@ -258,7 +258,7 @@ class TempoMap : public PBD::StatefulDestructible
 
 	nframes_t frame_rate () const { return _frame_rate; }
 
-	PBD::Signal1<void,PBD::Change> StateChanged;
+	PBD::Signal1<void,PBD::PropertyChange> StateChanged;
 
   private:
 	static Tempo    _default_tempo;
diff --git a/libs/ardour/ardour/types.h b/libs/ardour/ardour/types.h
index e8a8120591..4380662540 100644
--- a/libs/ardour/ardour/types.h
+++ b/libs/ardour/ardour/types.h
@@ -63,6 +63,11 @@ namespace ARDOUR {
 	 * don't want to pay for extremely long session times they don't need...
 	 */
 	typedef int64_t sframes_t;
+	typedef int64_t framepos_t;
+	/* any offset from a framepos_t, measured in audio frames */
+	typedef int64_t frameoffset_t;
+	/* any count of audio frames */
+	typedef int64_t framecnt_t;
 
 	enum IOChange {
 		NoChange = 0,
diff --git a/libs/ardour/audio_diskstream.cc b/libs/ardour/audio_diskstream.cc
index 9a93e45000..0ec6533aa4 100644
--- a/libs/ardour/audio_diskstream.cc
+++ b/libs/ardour/audio_diskstream.cc
@@ -344,7 +344,12 @@ AudioDiskstream::setup_destructive_playlist ()
 
 	/* a single full-sized region */
 
-	boost::shared_ptr<Region> region (RegionFactory::create (srcs, 0, max_frames - srcs.front()->natural_position(), _name));
+	PropertyList plist;
+	plist.add (Properties::name, _name.val());
+	plist.add (Properties::start, 0);
+	plist.add (Properties::length, max_frames - max_frames - srcs.front()->natural_position());
+
+	boost::shared_ptr<Region> region (RegionFactory::create (srcs, plist));
 	_playlist->add_region (region, srcs.front()->natural_position());
 }
 
@@ -1465,10 +1470,15 @@ AudioDiskstream::transport_stopped (struct tm& when, time_t twhen, bool abort_ca
 		*/
 
 		try {
-			boost::shared_ptr<Region> rx (RegionFactory::create (srcs,
-						c->front()->write_source->last_capture_start_frame(), total_capture,
-						whole_file_region_name, 0,
-						Region::Flag (Region::DefaultFlags|Region::Automatic|Region::WholeFile)));
+			PropertyList plist;
+
+			plist.add (Properties::start, c->front()->write_source->last_capture_start_frame());
+			plist.add (Properties::length, total_capture);
+			plist.add (Properties::name, whole_file_region_name);
+
+			boost::shared_ptr<Region> rx (RegionFactory::create (srcs, plist));
+			rx->set_automatic (true);
+			rx->set_whole_file (true);
 
 			region = boost::dynamic_pointer_cast<AudioRegion> (rx);
 			region->special_set_position (capture_info.front()->start);
@@ -1496,7 +1506,14 @@ AudioDiskstream::transport_stopped (struct tm& when, time_t twhen, bool abort_ca
 			// cerr << _name << ": based on ci of " << (*ci)->start << " for " << (*ci)->frames << " add region " << region_name << endl;
 
 			try {
-				boost::shared_ptr<Region> rx (RegionFactory::create (srcs, buffer_position, (*ci)->frames, region_name));
+
+				PropertyList plist;
+				
+				plist.add (Properties::start, buffer_position);
+				plist.add (Properties::length, (*ci)->frames);
+				plist.add (Properties::name, region_name);
+				
+				boost::shared_ptr<Region> rx (RegionFactory::create (srcs, plist));
 				region = boost::dynamic_pointer_cast<AudioRegion> (rx);
 			}
 
@@ -2196,10 +2213,17 @@ AudioDiskstream::use_pending_capture_data (XMLNode& node)
 	boost::shared_ptr<AudioRegion> region;
 
 	try {
-		region = boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (
-				pending_sources, 0, first_fs->length(first_fs->timeline_position()),
-				region_name_from_path (first_fs->name(), true), 0,
-				Region::Flag (Region::DefaultFlags|Region::Automatic|Region::WholeFile)));
+		
+		PropertyList plist;
+		
+		plist.add (Properties::start, 0);
+		plist.add (Properties::length, first_fs->length (first_fs->timeline_position()));
+		plist.add (Properties::name, region_name_from_path (first_fs->name(), true));
+
+		region = boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (pending_sources, plist));
+
+		region->set_automatic (true);
+		region->set_whole_file (true);
 		region->special_set_position (0);
 	}
 
@@ -2211,20 +2235,6 @@ AudioDiskstream::use_pending_capture_data (XMLNode& node)
 		return -1;
 	}
 
-	try {
-		region = boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (
-				pending_sources, 0, first_fs->length(first_fs->timeline_position()),
-				region_name_from_path (first_fs->name(), true)));
-	}
-
-	catch (failed_constructor& err) {
-		error << string_compose (_("%1: cannot create region from pending capture sources"),
-				  _name)
-		      << endmsg;
-
-		return -1;
-	}
-
 	_playlist->add_region (region, position);
 
 	return 0;
diff --git a/libs/ardour/audio_playlist.cc b/libs/ardour/audio_playlist.cc
index 7f75d44852..60c7d4bdc3 100644
--- a/libs/ardour/audio_playlist.cc
+++ b/libs/ardour/audio_playlist.cc
@@ -420,7 +420,7 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
 				   audio engineering.
 				*/
 
-				xfade_length = min ((nframes_t) 720, top->length());
+				xfade_length = min ((framecnt_t) 720, top->length());
 
 				if (top_region_at (top->first_frame()) == top) {
 
@@ -454,7 +454,7 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
 				} else {
 
 					touched_regions = regions_touched (top->first_frame(),
-									   top->first_frame() + min ((nframes_t)_session.config.get_short_xfade_seconds() * _session.frame_rate(),
+									   top->first_frame() + min ((framecnt_t) _session.config.get_short_xfade_seconds() * _session.frame_rate(),
 												     top->length()));
 					if (touched_regions->size() <= 2) {
 						xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, _session.config.get_xfade_model(), _session.config.get_xfades_active()));
@@ -480,7 +480,7 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
 
 				} else {
 					touched_regions = regions_touched (bottom->first_frame(),
-									   bottom->first_frame() + min ((nframes_t)_session.config.get_short_xfade_seconds() * _session.frame_rate(),
+									   bottom->first_frame() + min ((framecnt_t)_session.config.get_short_xfade_seconds() * _session.frame_rate(),
 													bottom->length()));
 					if (touched_regions->size() <= 2) {
 						xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, _session.config.get_xfade_model(), _session.config.get_xfades_active()));
@@ -726,7 +726,7 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
 }
 
 void
-AudioPlaylist::crossfade_changed (Change)
+AudioPlaylist::crossfade_changed (PropertyChange)
 {
 	if (in_flush || in_set_state) {
 		return;
@@ -742,13 +742,13 @@ AudioPlaylist::crossfade_changed (Change)
 }
 
 bool
-AudioPlaylist::region_changed (Change what_changed, boost::shared_ptr<Region> region)
+AudioPlaylist::region_changed (PropertyChange what_changed, boost::shared_ptr<Region> region)
 {
 	if (in_flush || in_set_state) {
 		return false;
 	}
 
-	Change our_interests = Change (AudioRegion::FadeInChanged|
+	PropertyChange our_interests = PropertyChange (AudioRegion::FadeInChanged|
 				       AudioRegion::FadeOutChanged|
 				       AudioRegion::FadeInActiveChanged|
 				       AudioRegion::FadeOutActiveChanged|
diff --git a/libs/ardour/audio_track.cc b/libs/ardour/audio_track.cc
index 502c3a7220..ebc7a9be66 100644
--- a/libs/ardour/audio_track.cc
+++ b/libs/ardour/audio_track.cc
@@ -770,11 +770,14 @@ AudioTrack::freeze (InterThreadInfo& itt)
 
 	/* create a new region from all filesources, keep it private */
 
-	boost::shared_ptr<Region> region (RegionFactory::create (srcs, 0,
-			srcs[0]->length(srcs[0]->timeline_position()),
-			region_name, 0,
-			(Region::Flag) (Region::WholeFile|Region::DefaultFlags),
-			false));
+	PropertyList plist;
+	
+	plist.add (Properties::start, 0);
+	plist.add (Properties::length, srcs[0]->length(srcs[0]->timeline_position()));
+	plist.add (Properties::name, region_name);
+	plist.add (Properties::whole_file, true);
+
+	boost::shared_ptr<Region> region (RegionFactory::create (srcs, plist, false));
 
 	new_playlist->set_orig_diskstream_id (diskstream->id());
 	new_playlist->add_region (region, _session.current_start_frame());
diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index d1e78cadd3..f1af3b6fab 100644
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -36,6 +36,7 @@
 #include "evoral/Curve.hpp"
 
 #include "ardour/audioregion.h"
+#include "ardour/debug.h"
 #include "ardour/session.h"
 #include "ardour/gain.h"
 #include "ardour/dB.h"
@@ -52,186 +53,180 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
-/* a Session will reset these to its chosen defaults by calling AudioRegion::set_default_fade() */
+namespace ARDOUR {
+	namespace Properties {
+		PBD::PropertyDescriptor<bool> envelope_active;
+		PBD::PropertyDescriptor<bool> default_fade_in;
+		PBD::PropertyDescriptor<bool> default_fade_out;
+		PBD::PropertyDescriptor<bool> fade_in_active;
+		PBD::PropertyDescriptor<bool> fade_out_active;
+		PBD::PropertyDescriptor<float> scale_amplitude;
+	}
+}
 
-Change AudioRegion::FadeInChanged         = PBD::new_change();
-Change AudioRegion::FadeOutChanged        = PBD::new_change();
-Change AudioRegion::FadeInActiveChanged   = PBD::new_change();
-Change AudioRegion::FadeOutActiveChanged  = PBD::new_change();
-Change AudioRegion::EnvelopeActiveChanged = PBD::new_change();
-Change AudioRegion::ScaleAmplitudeChanged = PBD::new_change();
-Change AudioRegion::EnvelopeChanged       = PBD::new_change();
+void
+AudioRegion::make_property_quarks ()
+{
+	Properties::envelope_active.id = g_quark_from_static_string (X_("envelope-active"));
+	Properties::default_fade_in.id = g_quark_from_static_string (X_("default-fade-in"));
+	Properties::default_fade_out.id = g_quark_from_static_string (X_("default-fade-out"));
+	Properties::fade_in_active.id = g_quark_from_static_string (X_("fade-in-active"));
+	Properties::fade_out_active.id = g_quark_from_static_string (X_("fade-out-active"));
+	Properties::scale_amplitude.id = g_quark_from_static_string (X_("scale-amplitude"));
+}
+
+void
+AudioRegion::register_properties ()
+{
+	/* no need to register parent class properties */
+
+	add_property (_envelope_active);
+	add_property (_default_fade_in);
+	add_property (_default_fade_out);
+	add_property (_fade_in_active);
+	add_property (_fade_out_active);
+	add_property (_scale_amplitude);
+}
+
+#define AUDIOREGION_STATE_DEFAULT \
+	_envelope_active (Properties::envelope_active, EnvelopeActiveChanged, false) \
+	, _default_fade_in (Properties::default_fade_in, FadeInChanged, true) \
+	, _default_fade_out (Properties::default_fade_out, FadeOutChanged, true) \
+	, _fade_in_active (Properties::fade_in_active, FadeInActiveChanged, true) \
+	, _fade_out_active (Properties::fade_out_active, FadeOutActiveChanged, true) \
+	, _scale_amplitude (Properties::scale_amplitude, ScaleAmplitudeChanged, 1.0)
+
+#define AUDIOREGION_COPY_STATE(other) \
+	 _envelope_active (other->_envelope_active) \
+	, _default_fade_in (other->_default_fade_in) \
+	, _default_fade_out (other->_default_fade_out) \
+        , _fade_in_active (other->_fade_in_active) \
+        , _fade_out_active (other->_fade_out_active) \
+	, _scale_amplitude (other->_scale_amplitude) 
+
+PropertyChange AudioRegion::FadeInChanged         = PBD::new_change();
+PropertyChange AudioRegion::FadeOutChanged        = PBD::new_change();
+PropertyChange AudioRegion::FadeInActiveChanged   = PBD::new_change();
+PropertyChange AudioRegion::FadeOutActiveChanged  = PBD::new_change();
+PropertyChange AudioRegion::EnvelopeActiveChanged = PBD::new_change();
+PropertyChange AudioRegion::ScaleAmplitudeChanged = PBD::new_change();
+PropertyChange AudioRegion::EnvelopeChanged       = PBD::new_change();
+
+/* a Session will reset these to its chosen defaults by calling AudioRegion::set_default_fade() */
 
 void
 AudioRegion::init ()
 {
-	_scale_amplitude = 1.0;
+	register_properties ();
 
 	set_default_fades ();
 	set_default_envelope ();
 
 	listen_to_my_curves ();
 	connect_to_analysis_changed ();
+	connect_to_header_position_offset_changed ();
 }
 
 /** Constructor for use by derived types only */
-AudioRegion::AudioRegion (Session& s, nframes_t start, nframes_t length, string name)
-	: Region (s, start, length, name, DataType::AUDIO)
-	, _automatable(s)
+AudioRegion::AudioRegion (Session& s, framepos_t start, framecnt_t len, std::string name)
+	: Region (s, start, len, name, DataType::AUDIO)
+	, AUDIOREGION_STATE_DEFAULT
+	, _automatable (s)
 	, _fade_in (new AutomationList(Evoral::Parameter(FadeInAutomation)))
 	, _fade_out (new AutomationList(Evoral::Parameter(FadeOutAutomation)))
 	, _envelope (new AutomationList(Evoral::Parameter(EnvelopeAutomation)))
+	, _fade_in_suspended (0)
+	, _fade_out_suspended (0)
 {
 	init ();
 	assert (_sources.size() == _master_sources.size());
 }
 
 /** Basic AudioRegion constructor (one channel) */
-AudioRegion::AudioRegion (boost::shared_ptr<AudioSource> src, nframes_t start, nframes_t length)
-	: Region (src, start, length, PBD::basename_nosuffix(src->name()), DataType::AUDIO, 0,  Region::Flag(Region::DefaultFlags|Region::External))
+AudioRegion::AudioRegion (boost::shared_ptr<AudioSource> src)
+	: Region (boost::static_pointer_cast<Source>(src))
+	, AUDIOREGION_STATE_DEFAULT
 	, _automatable(src->session())
 	, _fade_in (new AutomationList(Evoral::Parameter(FadeInAutomation)))
 	, _fade_out (new AutomationList(Evoral::Parameter(FadeOutAutomation)))
 	, _envelope (new AutomationList(Evoral::Parameter(EnvelopeAutomation)))
+	, _fade_in_suspended (0)
+	, _fade_out_suspended (0)
 {
-	boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource> (src);
-	if (afs) {
-		afs->HeaderPositionOffsetChanged.connect_same_thread (*this, boost::bind (&AudioRegion::source_offset_changed, this));
-	}
-
 	init ();
-	assert (_sources.size() == _master_sources.size());
-}
-
-/* Basic AudioRegion constructor (one channel) */
-AudioRegion::AudioRegion (boost::shared_ptr<AudioSource> src, nframes_t start, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: Region (src, start, length, name, DataType::AUDIO, layer, flags)
-	, _automatable(src->session())
-	, _fade_in (new AutomationList(Evoral::Parameter(FadeInAutomation)))
-	, _fade_out (new AutomationList(Evoral::Parameter(FadeOutAutomation)))
-	, _envelope (new AutomationList(Evoral::Parameter(EnvelopeAutomation)))
-{
-	boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource> (src);
-	if (afs) {
-		afs->HeaderPositionOffsetChanged.connect_same_thread (*this, boost::bind (&AudioRegion::source_offset_changed, this));
-	}
+	
+	/* XXX why is this set here ? - set in a property list given to RegionFactory */
+	_external = true;
 
-	init ();
 	assert (_sources.size() == _master_sources.size());
 }
 
 /** Basic AudioRegion constructor (many channels) */
-AudioRegion::AudioRegion (const SourceList& srcs, nframes_t start, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: Region (srcs, start, length, name, DataType::AUDIO, layer, flags)
+AudioRegion::AudioRegion (const SourceList& srcs)
+	: Region (srcs)
+	, AUDIOREGION_STATE_DEFAULT
 	, _automatable(srcs[0]->session())
 	, _fade_in (new AutomationList(Evoral::Parameter(FadeInAutomation)))
 	, _fade_out (new AutomationList(Evoral::Parameter(FadeOutAutomation)))
 	, _envelope (new AutomationList(Evoral::Parameter(EnvelopeAutomation)))
+	, _fade_in_suspended (0)
+	, _fade_out_suspended (0)
 {
 	init ();
-	connect_to_analysis_changed ();
-	assert (_sources.size() == _master_sources.size());
-}
-
-/** Create a new AudioRegion, that is part of an existing one */
-AudioRegion::AudioRegion (boost::shared_ptr<const AudioRegion> other, nframes_t offset, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: Region (other, offset, length, name, layer, flags)
-	, _automatable(other->session())
-	, _fade_in (new AutomationList(*other->_fade_in))
-	, _fade_out (new AutomationList(*other->_fade_out))
-	, _envelope (new AutomationList(*other->_envelope, offset, offset + length))
-{
-	connect_to_header_position_offset_changed ();
-
-	/* return to default fades if the existing ones are too long */
-
-	if (_flags & LeftOfSplit) {
-		if (_fade_in->back()->when >= _length) {
-			set_default_fade_in ();
-		} else {
-			_fade_in_disabled = other->_fade_in_disabled;
-		}
-		set_default_fade_out ();
-		_flags = Flag (_flags & ~Region::LeftOfSplit);
-	}
-
-	if (_flags & RightOfSplit) {
-		if (_fade_out->back()->when >= _length) {
-			set_default_fade_out ();
-		} else {
-			_fade_out_disabled = other->_fade_out_disabled;
-		}
-		set_default_fade_in ();
-		_flags = Flag (_flags & ~Region::RightOfSplit);
-	}
-
-	_scale_amplitude = other->_scale_amplitude;
-
-	assert(_type == DataType::AUDIO);
-
-	listen_to_my_curves ();
-	connect_to_analysis_changed ();
-
 	assert (_sources.size() == _master_sources.size());
 }
 
-AudioRegion::AudioRegion (boost::shared_ptr<const AudioRegion> other)
-	: Region (other)
+AudioRegion::AudioRegion (boost::shared_ptr<const AudioRegion> other, nframes64_t offset, bool offset_relative)
+	: Region (other, offset, offset_relative)
+	, AUDIOREGION_COPY_STATE (other)
 	, _automatable (other->session())
 	, _fade_in (new AutomationList (*other->_fade_in))
 	, _fade_out (new AutomationList (*other->_fade_out))
-	, _envelope (new AutomationList (*other->_envelope))
+	  /* XXX is this guaranteed to work for all values of offset+offset_relative? */
+	, _envelope (new AutomationList (*other->_envelope, _start, _start + _length))
+	, _fade_in_suspended (0)
+	, _fade_out_suspended (0)
 {
-	assert(_type == DataType::AUDIO);
-	_scale_amplitude = other->_scale_amplitude;
-
+	/* don't use init here, because we got fade in/out from the other region
+	*/
+	register_properties ();
 	listen_to_my_curves ();
 	connect_to_analysis_changed ();
+	connect_to_header_position_offset_changed ();
 
+	assert(_type == DataType::AUDIO);
 	assert (_sources.size() == _master_sources.size());
 }
 
-AudioRegion::AudioRegion (boost::shared_ptr<const AudioRegion> other, const SourceList& /*srcs*/,
-			  nframes_t length, const string& name, layer_t layer, Flag flags)
-	: Region (other, length, name, layer, flags)
+AudioRegion::AudioRegion (boost::shared_ptr<const AudioRegion> other, const SourceList& srcs)
+	: Region (boost::static_pointer_cast<const Region>(other), srcs)
+	, AUDIOREGION_COPY_STATE (other)
 	, _automatable (other->session())
 	, _fade_in (new AutomationList (*other->_fade_in))
 	, _fade_out (new AutomationList (*other->_fade_out))
 	, _envelope (new AutomationList (*other->_envelope))
+	, _fade_in_suspended (0)
+	, _fade_out_suspended (0)
 {
 	/* make-a-sort-of-copy-with-different-sources constructor (used by audio filter) */
 
-	for (SourceList::const_iterator i = _sources.begin(); i != _sources.end(); ++i) {
-
-		boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource> ((*i));
-		if (afs) {
-			afs->HeaderPositionOffsetChanged.connect_same_thread (*this, boost::bind (&AudioRegion::source_offset_changed, this));
-		}
-	}
-
-	_scale_amplitude = other->_scale_amplitude;
-
-	_fade_in_disabled = 0;
-	_fade_out_disabled = 0;
+	register_properties ();
 
 	listen_to_my_curves ();
 	connect_to_analysis_changed ();
+	connect_to_header_position_offset_changed ();
 
 	assert (_sources.size() == _master_sources.size());
 }
 
 AudioRegion::AudioRegion (boost::shared_ptr<AudioSource> src, const XMLNode& node)
 	: Region (src, node)
+	, AUDIOREGION_STATE_DEFAULT
 	, _automatable(src->session())
 	, _fade_in (new AutomationList(Evoral::Parameter(FadeInAutomation)))
 	, _fade_out (new AutomationList(Evoral::Parameter(FadeOutAutomation)))
 	, _envelope (new AutomationList(Evoral::Parameter(EnvelopeAutomation)))
 {
-	boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource> (src);
-	if (afs) {
-		afs->HeaderPositionOffsetChanged.connect_same_thread (*this, boost::bind (&AudioRegion::source_offset_changed, this));
-	}
-
 	init ();
 
 	if (set_state (node, Stateful::loading_state_version)) {
@@ -239,17 +234,18 @@ AudioRegion::AudioRegion (boost::shared_ptr<AudioSource> src, const XMLNode& nod
 	}
 
 	assert(_type == DataType::AUDIO);
-	connect_to_analysis_changed ();
-
 	assert (_sources.size() == _master_sources.size());
 }
 
 AudioRegion::AudioRegion (SourceList& srcs, const XMLNode& node)
 	: Region (srcs, node)
+	, AUDIOREGION_STATE_DEFAULT
 	, _automatable(srcs[0]->session())
 	, _fade_in (new AutomationList(Evoral::Parameter(FadeInAutomation)))
 	, _fade_out (new AutomationList(Evoral::Parameter(FadeOutAutomation)))
 	, _envelope (new AutomationList(Evoral::Parameter(EnvelopeAutomation)))
+	, _fade_in_suspended (0)
+	, _fade_out_suspended (0)
 {
 	init ();
 
@@ -267,6 +263,33 @@ AudioRegion::~AudioRegion ()
 }
 
 void
+AudioRegion::post_set ()
+{
+	if (!_sync_marked) {
+		_sync_position = _start;
+	}
+
+	/* return to default fades if the existing ones are too long */
+
+	if (_left_of_split) {
+		if (_fade_in->back()->when >= _length) {
+			set_default_fade_in ();
+		} 
+		set_default_fade_out ();
+		_left_of_split = false;
+	}
+
+	if (_right_of_split) {
+		if (_fade_out->back()->when >= _length) {
+			set_default_fade_out ();
+		} 
+
+		set_default_fade_in ();
+		_right_of_split = false;
+	}
+}
+
+void
 AudioRegion::connect_to_analysis_changed ()
 {
 	for (SourceList::const_iterator i = _sources.begin(); i != _sources.end(); ++i) {
@@ -294,8 +317,6 @@ AudioRegion::connect_to_header_position_offset_changed ()
 void
 AudioRegion::listen_to_my_curves ()
 {
-	cerr << _name << ": listeing my own curves\n";
-
 	_envelope->StateChanged.connect_same_thread (*this, boost::bind (&AudioRegion::envelope_changed, this));
 	_fade_in->StateChanged.connect_same_thread (*this, boost::bind (&AudioRegion::fade_in_changed, this));
 	_fade_out->StateChanged.connect_same_thread (*this, boost::bind (&AudioRegion::fade_out_changed, this));
@@ -305,11 +326,7 @@ void
 AudioRegion::set_envelope_active (bool yn)
 {
 	if (envelope_active() != yn) {
-		if (yn) {
-			_flags = Flag (_flags|EnvelopeActive);
-		} else {
-			_flags = Flag (_flags & ~EnvelopeActive);
-		}
+		_envelope_active = yn;
 		send_change (EnvelopeActiveChanged);
 	}
 }
@@ -324,7 +341,7 @@ AudioRegion::read_peaks (PeakData *buf, nframes_t npeaks, nframes_t offset, nfra
 	if (audio_source(chan_n)->read_peaks (buf, npeaks, offset, cnt, samples_per_unit)) {
 		return 0;
 	} else {
-		if (_scale_amplitude != 1.0) {
+		if (_scale_amplitude != 1.0f) {
 			for (nframes_t n = 0; n < npeaks; ++n) {
 				buf[n].max *= _scale_amplitude;
 				buf[n].min *= _scale_amplitude;
@@ -334,32 +351,32 @@ AudioRegion::read_peaks (PeakData *buf, nframes_t npeaks, nframes_t offset, nfra
 	}
 }
 
-nframes_t
-AudioRegion::read (Sample* buf, sframes_t timeline_position, nframes_t cnt, int channel) const
+framecnt_t
+AudioRegion::read (Sample* buf, framepos_t timeline_position, framecnt_t cnt, int channel) const
 {
 	/* raw read, no fades, no gain, nada */
 	return _read_at (_sources, _length, buf, 0, 0, _position + timeline_position, cnt, channel, 0, 0, ReadOps (0));
 }
 
-nframes_t
-AudioRegion::read_with_ops (Sample* buf, sframes_t file_position, nframes_t cnt, int channel, ReadOps rops) const
+framecnt_t
+AudioRegion::read_with_ops (Sample* buf, framepos_t file_position, framecnt_t cnt, int channel, ReadOps rops) const
 {
 	return _read_at (_sources, _length, buf, 0, 0, file_position, cnt, channel, 0, 0, rops);
 }
 
-nframes_t
+framecnt_t
 AudioRegion::read_at (Sample *buf, Sample *mixdown_buffer, float *gain_buffer,
-		sframes_t file_position, nframes_t cnt, uint32_t chan_n,
-		nframes_t read_frames, nframes_t skip_frames) const
+		      framepos_t file_position, framecnt_t cnt, uint32_t chan_n,
+		      framecnt_t read_frames, framecnt_t skip_frames) const
 {
 	/* regular diskstream/butler read complete with fades etc */
 	return _read_at (_sources, _length, buf, mixdown_buffer, gain_buffer,
 			file_position, cnt, chan_n, read_frames, skip_frames, ReadOps (~0));
 }
 
-nframes_t
+framecnt_t
 AudioRegion::master_read_at (Sample *buf, Sample *mixdown_buffer, float *gain_buffer,
-		sframes_t position, nframes_t cnt, uint32_t chan_n) const
+			     framepos_t position, framecnt_t cnt, uint32_t chan_n) const
 {
 	/* do not read gain/scaling/fades and do not count this disk i/o in statistics */
 
@@ -367,18 +384,19 @@ AudioRegion::master_read_at (Sample *buf, Sample *mixdown_buffer, float *gain_bu
 			 buf, mixdown_buffer, gain_buffer, position, cnt, chan_n, 0, 0, ReadOps (0));
 }
 
-nframes_t
-AudioRegion::_read_at (const SourceList& /*srcs*/, nframes_t limit,
-		Sample *buf, Sample *mixdown_buffer, float *gain_buffer,
-		sframes_t position, nframes_t cnt,
-		uint32_t chan_n,
-	        nframes_t /*read_frames*/,
-		nframes_t /*skip_frames*/,
-		ReadOps rops) const
+framecnt_t
+AudioRegion::_read_at (const SourceList& /*srcs*/, framecnt_t limit,
+		       Sample *buf, Sample *mixdown_buffer, float *gain_buffer,
+		       framepos_t position, 
+		       framecnt_t cnt,
+		       uint32_t chan_n,
+		       framecnt_t /*read_frames*/,
+		       framecnt_t /*skip_frames*/,
+		       ReadOps rops) const
 {
-	nframes_t internal_offset;
-	nframes_t buf_offset;
-	nframes_t to_read;
+	frameoffset_t internal_offset;
+	frameoffset_t buf_offset;
+	framecnt_t to_read;
 	bool raw = (rops == ReadOpsNone);
 
 	if (muted() && !raw) {
@@ -439,7 +457,7 @@ AudioRegion::_read_at (const SourceList& /*srcs*/, nframes_t limit,
 
 		/* fade in */
 
-		if ((_flags & FadeIn) && _session.config.get_use_region_fades()) {
+		if (_fade_in_active && _session.config.get_use_region_fades()) {
 
 			nframes_t fade_in_length = (nframes_t) _fade_in->back()->when;
 
@@ -462,7 +480,7 @@ AudioRegion::_read_at (const SourceList& /*srcs*/, nframes_t limit,
 
 		/* fade out */
 
-		if ((_flags & FadeOut) && _session.config.get_use_region_fades()) {
+		if (_fade_out_active && _session.config.get_use_region_fades()) {
 
 			/* see if some part of this read is within the fade out */
 
@@ -552,8 +570,6 @@ AudioRegion::state (bool full)
 	char buf2[64];
 	LocaleGuard lg (X_("POSIX"));
 
-	snprintf (buf, sizeof(buf), "%.12g", _scale_amplitude);
-	node.add_property ("scale-gain", buf);
 
 	// XXX these should move into Region
 
@@ -573,26 +589,7 @@ AudioRegion::state (bool full)
 	node.add_property ("channels", buf);
 
 	if (full) {
-
-		child = node.add_child (X_("FadeIn"));
-
-		if ((_flags & DefaultFadeIn)) {
-			child->add_property (X_("default"), X_("yes"));
-		} else {
-			child->add_child_nocopy (_fade_in->get_state ());
-		}
-
-		child->add_property (X_("active"), fade_in_active () ? X_("yes") : X_("no"));
-
-		child = node.add_child (X_("FadeOut"));
-
-		if ((_flags & DefaultFadeOut)) {
-			child->add_property (X_("default"), X_("yes"));
-		} else {
-			child->add_child_nocopy (_fade_out->get_state ());
-		}
-
-		child->add_property (X_("active"), fade_out_active () ? X_("yes") : X_("no"));
+		Stateful::add_properties (node);
 	}
 
 	child = node.add_child ("Envelope");
@@ -629,7 +626,7 @@ AudioRegion::state (bool full)
 }
 
 int
-AudioRegion::set_live_state (const XMLNode& node, int version, Change& what_changed, bool send)
+AudioRegion::_set_state (const XMLNode& node, int version, PropertyChange& what_changed, bool send)
 {
 	const XMLNodeList& nlist = node.children();
 	const XMLProperty *prop;
@@ -637,36 +634,32 @@ AudioRegion::set_live_state (const XMLNode& node, int version, Change& what_chan
 	boost::shared_ptr<Playlist> the_playlist (_playlist.lock());	
 
 	freeze ();
+
 	if (the_playlist) {
 		the_playlist->freeze ();
 	}
 
-	Region::set_live_state (node, version, what_changed, false);
-	cerr << "After region SLS, wc = " << what_changed << endl;
 
+	/* this will set all our State members and stuff controlled by the Region.
+	   It should NOT send any changed signals - that is our responsibility.
+	*/
 
-	if ((prop = node.property ("flags")) != 0) {
-		_flags = Flag (_flags & ~Region::LeftOfSplit);
-		_flags = Flag (_flags & ~Region::RightOfSplit);
-	}
-
-	/* find out if any flags changed that we signal about */
+	Region::_set_state (node, version, what_changed, false);
 
 	if ((prop = node.property ("scale-gain")) != 0) {
 		float a = atof (prop->value().c_str());
 		if (a != _scale_amplitude) {
 			_scale_amplitude = a;
-			what_changed = Change (what_changed|ScaleAmplitudeChanged);
+			what_changed = PropertyChange (what_changed|ScaleAmplitudeChanged);
 			cerr << _name << " amp changed\n";
 		}
 	}
 
-	/* Now find envelope description and other misc child items */
+	/* Now find envelope description and other related child items */
 
 	_envelope->freeze ();
 
 	for (XMLNodeConstIterator niter = nlist.begin(); niter != nlist.end(); ++niter) {
-#if 0
 		XMLNode *child;
 		XMLProperty *prop;
 
@@ -731,7 +724,6 @@ AudioRegion::set_live_state (const XMLNode& node, int version, Change& what_chan
 			cerr << _name << " fadeout changd\n";
 
 		}
-#endif
 	}
 
 	_envelope->thaw ();
@@ -749,15 +741,61 @@ AudioRegion::set_live_state (const XMLNode& node, int version, Change& what_chan
 	return 0;
 }
 
+PropertyChange
+AudioRegion::set_property (const PropertyBase& prop)
+{
+	PropertyChange c = PropertyChange (0);
+
+	DEBUG_TRACE (DEBUG::Properties,  string_compose ("audio region %1 set property %2\n", _name.val(), prop.property_name()));
+
+	if (prop == Properties::envelope_active.id) {
+		bool val = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+		if (val != _envelope_active) {
+			_envelope_active = val;
+			c = EnvelopeActiveChanged;
+		}
+	} else if (prop == Properties::default_fade_in.id) {
+		bool val = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+		if (val != _default_fade_in) {
+			_default_fade_in = val;
+			c = FadeInChanged;
+		}
+	} else if (prop == Properties::default_fade_out.id) {
+		bool val = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+		if (val != _default_fade_out) {
+			_default_fade_out = val;
+			c = FadeOutChanged;
+		}
+	} else if (prop == Properties::fade_in_active.id) {
+		bool val = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+		if (val != _fade_in_active) {
+			_fade_in_active = val;
+			c = FadeInActiveChanged;
+		}
+	} else if (prop == Properties::fade_out_active.id) {
+		bool val = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+		if (val != _fade_out_active) {
+			_fade_out_active = val;
+			c = FadeOutChanged;
+		}
+	} else if (prop == Properties::scale_amplitude.id) {
+		gain_t val = dynamic_cast<const PropertyTemplate<gain_t>*>(&prop)->val();
+		if (val != _scale_amplitude) {
+			_scale_amplitude = val;
+			c = ScaleAmplitudeChanged;
+		}
+	} else {
+		return Region::set_property (prop);
+	}
+
+	return c;
+}
+
 int
 AudioRegion::set_state (const XMLNode& node, int version)
 {
-	/* Region::set_state() calls the virtual set_live_state(),
-	   which will get us back to AudioRegion::set_live_state()
-	   to handle the relevant stuff.
-	*/
-
-	return Region::set_state (node, version);
+	PropertyChange what_changed;
+	return _set_state (node, version, what_changed, true);
 }
 
 void
@@ -783,7 +821,7 @@ AudioRegion::set_fade_in (boost::shared_ptr<AutomationList> f)
 }
 
 void
-AudioRegion::set_fade_in (FadeShape shape, nframes_t len)
+AudioRegion::set_fade_in (FadeShape shape, framecnt_t len)
 {
 	_fade_in->freeze ();
 	_fade_in->clear ();
@@ -850,7 +888,7 @@ AudioRegion::set_fade_out (boost::shared_ptr<AutomationList> f)
 }
 
 void
-AudioRegion::set_fade_out (FadeShape shape, nframes_t len)
+AudioRegion::set_fade_out (FadeShape shape, framecnt_t len)
 {
 	_fade_out->freeze ();
 	_fade_out->clear ();
@@ -905,7 +943,7 @@ AudioRegion::set_fade_out (FadeShape shape, nframes_t len)
 }
 
 void
-AudioRegion::set_fade_in_length (nframes_t len)
+AudioRegion::set_fade_in_length (framecnt_t len)
 {
 	if (len > _length) {
 		len = _length - 1;
@@ -914,13 +952,13 @@ AudioRegion::set_fade_in_length (nframes_t len)
 	bool changed = _fade_in->extend_to (len);
 
 	if (changed) {
-		_flags = Flag (_flags & ~DefaultFadeIn);
+		_default_fade_in = false;
 		send_change (FadeInChanged);
 	}
 }
 
 void
-AudioRegion::set_fade_out_length (nframes_t len)
+AudioRegion::set_fade_out_length (framecnt_t len)
 {
 	if (len > _length) {
 		len = _length - 1;
@@ -929,7 +967,7 @@ AudioRegion::set_fade_out_length (nframes_t len)
 	bool changed =	_fade_out->extend_to (len);
 
 	if (changed) {
-		_flags = Flag (_flags & ~DefaultFadeOut);
+		_default_fade_out = false;
 		send_change (FadeOutChanged);
 	}
 }
@@ -937,30 +975,21 @@ AudioRegion::set_fade_out_length (nframes_t len)
 void
 AudioRegion::set_fade_in_active (bool yn)
 {
-	if (yn == (_flags & FadeIn)) {
+	if (yn == _fade_in_active) {
 		return;
 	}
-	if (yn) {
-		_flags = Flag (_flags|FadeIn);
-	} else {
-		_flags = Flag (_flags & ~FadeIn);
-	}
 
+	_fade_in_active = yn;
 	send_change (FadeInActiveChanged);
 }
 
 void
 AudioRegion::set_fade_out_active (bool yn)
 {
-	if (yn == (_flags & FadeOut)) {
+	if (yn == _fade_out_active) {
 		return;
 	}
-	if (yn) {
-		_flags = Flag (_flags | FadeOut);
-	} else {
-		_flags = Flag (_flags & ~FadeOut);
-	}
-
+	_fade_out_active = yn;
 	send_change (FadeOutActiveChanged);
 }
 
@@ -979,14 +1008,14 @@ AudioRegion::fade_out_is_default () const
 void
 AudioRegion::set_default_fade_in ()
 {
-	_fade_in_disabled = 0;
+	_fade_in_suspended = 0;
 	set_fade_in (Linear, 64);
 }
 
 void
 AudioRegion::set_default_fade_out ()
 {
-	_fade_out_disabled = 0;
+	_fade_out_suspended = 0;
 	set_fade_out (Linear, 64);
 }
 
@@ -1080,9 +1109,15 @@ AudioRegion::separate_by_channel (Session& /*session*/, vector<boost::shared_ptr
 		   "whole file" even if it covers the entire source file(s).
 		 */
 
-		Flag f = Flag (_flags & ~WholeFile);
+		PropertyList plist;
+		
+		plist.add (Properties::start, _start.val());
+		plist.add (Properties::length, _length.val());
+		plist.add (Properties::name, new_name);
+		plist.add (Properties::layer, _layer.val());
 
-		v.push_back(RegionFactory::create (srcs, _start, _length, new_name, _layer, f));
+		v.push_back(RegionFactory::create (srcs, plist));
+		v.back()->set_whole_file (false);
 
 		++n;
 	}
@@ -1090,8 +1125,8 @@ AudioRegion::separate_by_channel (Session& /*session*/, vector<boost::shared_ptr
 	return 0;
 }
 
-nframes_t
-AudioRegion::read_raw_internal (Sample* buf, sframes_t pos, nframes_t cnt, int channel) const
+framecnt_t
+AudioRegion::read_raw_internal (Sample* buf, framepos_t pos, framecnt_t cnt, int channel) const
 {
 	return audio_source()->read (buf, pos, cnt, channel);
 }
@@ -1183,11 +1218,11 @@ AudioRegion::set_scale_amplitude (gain_t g)
 void
 AudioRegion::normalize_to (float target_dB)
 {
-	const nframes_t blocksize = 64 * 1024;
+	const framecnt_t blocksize = 64 * 1024;
 	Sample buf[blocksize];
-	nframes_t fpos;
-	nframes_t fend;
-	nframes_t to_read;
+	framepos_t fpos;
+	framepos_t fend;
+	framecnt_t to_read;
 	double maxamp = 0;
 	gain_t target = dB_to_coefficient (target_dB);
 
@@ -1271,7 +1306,7 @@ AudioRegion::envelope_changed ()
 void
 AudioRegion::suspend_fade_in ()
 {
-	if (++_fade_in_disabled == 1) {
+	if (++_fade_in_suspended == 1) {
 		if (fade_in_is_default()) {
 			set_fade_in_active (false);
 		}
@@ -1281,7 +1316,7 @@ AudioRegion::suspend_fade_in ()
 void
 AudioRegion::resume_fade_in ()
 {
-	if (--_fade_in_disabled == 0 && _fade_in_disabled) {
+	if (--_fade_in_suspended == 0 && _fade_in_suspended) {
 		set_fade_in_active (true);
 	}
 }
@@ -1289,7 +1324,7 @@ AudioRegion::resume_fade_in ()
 void
 AudioRegion::suspend_fade_out ()
 {
-	if (++_fade_out_disabled == 1) {
+	if (++_fade_out_suspended == 1) {
 		if (fade_out_is_default()) {
 			set_fade_out_active (false);
 		}
@@ -1299,7 +1334,7 @@ AudioRegion::suspend_fade_out ()
 void
 AudioRegion::resume_fade_out ()
 {
-	if (--_fade_out_disabled == 0 &&_fade_out_disabled) {
+	if (--_fade_out_suspended == 0 &&_fade_out_suspended) {
 		set_fade_out_active (true);
 	}
 }
@@ -1474,20 +1509,20 @@ then quit ardour and restart."));
  *  @return Silent periods; first of pair is the offset within the region, second is the length of the period
  */
 
-std::list<std::pair<nframes_t, nframes_t> >
-AudioRegion::find_silence (Sample threshold, nframes_t min_length) const
+std::list<std::pair<frameoffset_t, framecnt_t> >
+AudioRegion::find_silence (Sample threshold, framecnt_t min_length) const
 {
-	nframes_t const block_size = 64 * 1024;
+	framecnt_t const block_size = 64 * 1024;
 	Sample loudest[block_size];
 	Sample buf[block_size];
 
-	nframes_t pos = _start;
-	nframes_t const end = _start + _length - 1;
+	framepos_t pos = _start;
+	framepos_t const end = _start + _length - 1;
 
-	std::list<std::pair<nframes_t, nframes_t> > silent_periods;
+	std::list<std::pair<frameoffset_t, framecnt_t> > silent_periods;
 
 	bool in_silence = false;
-	nframes_t silence_start = 0;
+	frameoffset_t silence_start = 0;
 	bool silence;
 
 	while (pos < end) {
@@ -1497,13 +1532,13 @@ AudioRegion::find_silence (Sample threshold, nframes_t min_length) const
 		for (uint32_t n = 0; n < n_channels(); ++n) {
 
 			read_raw_internal (buf, pos, block_size, n);
-			for (nframes_t i = 0; i < block_size; ++i) {
+			for (framecnt_t i = 0; i < block_size; ++i) {
 				loudest[i] = max (loudest[i], abs (buf[i]));
 			}
 		}
 
 		/* now look for silence */
-		for (nframes_t i = 0; i < block_size; ++i) {
+		for (framecnt_t i = 0; i < block_size; ++i) {
 			silence = abs (loudest[i]) < threshold;
 			if (silence && !in_silence) {
 				/* non-silence to silence */
@@ -1530,11 +1565,12 @@ AudioRegion::find_silence (Sample threshold, nframes_t min_length) const
 }
 
 
+
 extern "C" {
 
 	int region_read_peaks_from_c (void *arg, uint32_t npeaks, uint32_t start, uint32_t cnt, intptr_t data, uint32_t n_chan, double samples_per_unit)
 {
-	return ((AudioRegion *) arg)->read_peaks ((PeakData *) data, (nframes_t) npeaks, (nframes_t) start, (nframes_t) cnt, n_chan,samples_per_unit);
+	return ((AudioRegion *) arg)->read_peaks ((PeakData *) data, (framecnt_t) npeaks, (framepos_t) start, (framecnt_t) cnt, n_chan,samples_per_unit);
 }
 
 uint32_t region_length_from_c (void *arg)
diff --git a/libs/ardour/audiosource.cc b/libs/ardour/audiosource.cc
index 0eb31c38b2..841dec1887 100644
--- a/libs/ardour/audiosource.cc
+++ b/libs/ardour/audiosource.cc
@@ -265,15 +265,15 @@ AudioSource::initialize_peakfile (bool newfile, ustring audio_path)
 	return 0;
 }
 
-nframes_t
-AudioSource::read (Sample *dst, sframes_t start, nframes_t cnt, int /*channel*/) const
+framecnt_t
+AudioSource::read (Sample *dst, framepos_t start, framecnt_t cnt, int /*channel*/) const
 {
 	Glib::Mutex::Lock lm (_lock);
 	return read_unlocked (dst, start, cnt);
 }
 
-nframes_t
-AudioSource::write (Sample *dst, nframes_t cnt)
+framecnt_t
+AudioSource::write (Sample *dst, framecnt_t cnt)
 {
 	Glib::Mutex::Lock lm (_lock);
 	/* any write makes the fill not removable */
@@ -282,7 +282,7 @@ AudioSource::write (Sample *dst, nframes_t cnt)
 }
 
 int
-AudioSource::read_peaks (PeakData *peaks, nframes_t npeaks, sframes_t start, nframes_t cnt, double samples_per_visual_peak) const
+AudioSource::read_peaks (PeakData *peaks, framecnt_t npeaks, framepos_t start, framecnt_t cnt, double samples_per_visual_peak) const
 {
 	return read_peaks_with_fpp (peaks, npeaks, start, cnt, samples_per_visual_peak, _FPP);
 }
@@ -292,8 +292,8 @@ AudioSource::read_peaks (PeakData *peaks, nframes_t npeaks, sframes_t start, nfr
  */
 
 int
-AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t start, nframes_t cnt,
-				  double samples_per_visual_peak, nframes_t samples_per_file_peak) const
+AudioSource::read_peaks_with_fpp (PeakData *peaks, framecnt_t npeaks, framepos_t start, framecnt_t cnt,
+				  double samples_per_visual_peak, framecnt_t samples_per_file_peak) const
 {
 	Glib::Mutex::Lock lm (_lock);
 	double scale;
@@ -302,7 +302,7 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t s
 	PeakData::PeakDatum xmin;
 	int32_t to_read;
 	uint32_t nread;
-	nframes_t zero_fill = 0;
+	framecnt_t zero_fill = 0;
 	int ret = -1;
 	PeakData* staging = 0;
 	Sample* raw_staging = 0;
@@ -329,8 +329,8 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t s
 	if (cnt > _length - start) {
 		// cerr << "too close to end @ " << _length << " given " << start << " + " << cnt << endl;
 		cnt = _length - start;
-		nframes_t old = npeaks;
-		npeaks = min ((nframes_t) floor (cnt / samples_per_visual_peak), npeaks);
+		framecnt_t old = npeaks;
+		npeaks = min ((framecnt_t) floor (cnt / samples_per_visual_peak), npeaks);
 		zero_fill = old - npeaks;
 	}
 
@@ -352,7 +352,7 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t s
 			return -1;
 		}
 
-		for (nframes_t i = 0; i < npeaks; ++i) {
+		for (framecnt_t i = 0; i < npeaks; ++i) {
 			peaks[i].max = raw_staging[i];
 			peaks[i].min = raw_staging[i];
 		}
@@ -403,7 +403,7 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t s
 	}
 
 
-	nframes_t tnp;
+	framecnt_t tnp;
 
 	if (scale < 1.0) {
 
@@ -420,20 +420,20 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t s
 		    to avoid confusion, I'll refer to the requested peaks as visual_peaks and the peakfile peaks as stored_peaks
 		*/
 
-		const uint32_t chunksize = (uint32_t) min (expected_peaks, 65536.0);
-
+		const framecnt_t chunksize = (framecnt_t) min (expected_peaks, 65536.0);
+		
 		staging = new PeakData[chunksize];
 
 		/* compute the rounded up frame position  */
 
-		nframes_t current_frame = start;
-		nframes_t current_stored_peak = (nframes_t) ceil (current_frame / (double) samples_per_file_peak);
-		uint32_t       next_visual_peak  = (uint32_t) ceil (current_frame / samples_per_visual_peak);
-		double         next_visual_peak_frame = next_visual_peak * samples_per_visual_peak;
-		uint32_t       stored_peak_before_next_visual_peak = (nframes_t) next_visual_peak_frame / samples_per_file_peak;
-		uint32_t       nvisual_peaks = 0;
-		uint32_t       stored_peaks_read = 0;
-		uint32_t       i = 0;
+		framepos_t current_frame = start;
+		framepos_t current_stored_peak = (framepos_t) ceil (current_frame / (double) samples_per_file_peak);
+		framepos_t next_visual_peak  = (framepos_t) ceil (current_frame / samples_per_visual_peak);
+		double     next_visual_peak_frame = next_visual_peak * samples_per_visual_peak;
+		framepos_t stored_peak_before_next_visual_peak = (framepos_t) next_visual_peak_frame / samples_per_file_peak;
+		framecnt_t nvisual_peaks = 0;
+		framecnt_t stored_peaks_read = 0;
+		framecnt_t i = 0;
 
 		/* handle the case where the initial visual peak is on a pixel boundary */
 
@@ -452,7 +452,7 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t s
 			if (i == stored_peaks_read) {
 
 				uint32_t       start_byte = current_stored_peak * sizeof(PeakData);
-				tnp = min ((nframes_t)(_length/samples_per_file_peak - current_stored_peak), (nframes_t) expected_peaks);
+				tnp = min ((framecnt_t)(_length/samples_per_file_peak - current_stored_peak), (framecnt_t) expected_peaks);
 				to_read = min (chunksize, tnp);
 
 #ifdef DEBUG_READ_PEAKS
@@ -527,14 +527,14 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t s
 		   data on the fly.
 		*/
 
-		nframes_t frames_read = 0;
-		nframes_t current_frame = start;
-		nframes_t i = 0;
-		nframes_t nvisual_peaks = 0;
-		nframes_t chunksize = (nframes_t) min (cnt, (nframes_t) 4096);
+		framecnt_t frames_read = 0;
+		framepos_t current_frame = start;
+		framecnt_t i = 0;
+		framecnt_t nvisual_peaks = 0;
+		framecnt_t chunksize = (framecnt_t) min (cnt, (framecnt_t) 4096);
 		raw_staging = new Sample[chunksize];
 
-		nframes_t frame_pos = start;
+		framepos_t frame_pos = start;
 		double pixel_pos = floor (frame_pos / samples_per_visual_peak);
 		double next_pixel_pos = ceil (frame_pos / samples_per_visual_peak);
 		double pixels_per_frame = 1.0 / samples_per_visual_peak;
@@ -546,7 +546,7 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t s
 
 			if (i == frames_read) {
 
-				to_read = min (chunksize, nframes_t(_length - current_frame));
+				to_read = min (chunksize, (framecnt_t)(_length - current_frame));
 
 				if (to_read == 0) {
 					/* XXX ARGH .. out by one error ... need to figure out why this happens
@@ -612,12 +612,12 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t s
 int
 AudioSource::build_peaks_from_scratch ()
 {
-	nframes_t current_frame;
-	nframes_t cnt;
+	framepos_t current_frame;
+	framecnt_t cnt;
 	Sample* buf = 0;
-	nframes_t frames_read;
-	nframes_t frames_to_read;
-	const nframes_t bufsize = 65536; // 256kB per disk read for mono data is about ideal
+	framecnt_t frames_read;
+	framecnt_t frames_to_read;
+	const framecnt_t bufsize = 65536; // 256kB per disk read for mono data is about ideal
 
 	int ret = -1;
 
@@ -708,23 +708,23 @@ AudioSource::done_with_peakfile_writes (bool done)
 }
 
 int
-AudioSource::compute_and_write_peaks (Sample* buf, sframes_t first_frame, nframes_t cnt,
-		bool force, bool intermediate_peaks_ready)
+AudioSource::compute_and_write_peaks (Sample* buf, framepos_t first_frame, framecnt_t cnt,
+				      bool force, bool intermediate_peaks_ready)
 {
 	return compute_and_write_peaks (buf, first_frame, cnt, force, intermediate_peaks_ready, _FPP);
 }
 
 int
-AudioSource::compute_and_write_peaks (Sample* buf, sframes_t first_frame, nframes_t cnt,
-		bool force, bool intermediate_peaks_ready, nframes_t fpp)
+AudioSource::compute_and_write_peaks (Sample* buf, framepos_t first_frame, framecnt_t cnt,
+				      bool force, bool intermediate_peaks_ready, framecnt_t fpp)
 {
 	Sample* buf2 = 0;
-	nframes_t to_do;
+	framecnt_t to_do;
 	uint32_t  peaks_computed;
 	PeakData* peakbuf = 0;
 	int ret = -1;
-	nframes_t current_frame;
-	nframes_t frames_done;
+	framepos_t current_frame;
+	framecnt_t frames_done;
 	const size_t blocksize = (128 * 1024);
 	off_t first_peak_byte;
 
@@ -828,7 +828,7 @@ AudioSource::compute_and_write_peaks (Sample* buf, sframes_t first_frame, nframe
 			break;
 		}
 
-		nframes_t this_time = min (fpp, to_do);
+		framecnt_t this_time = min (fpp, to_do);
 
 		peakbuf[peaks_computed].max = buf[0];
 		peakbuf[peaks_computed].min = buf[0];
@@ -903,7 +903,7 @@ AudioSource::truncate_peakfile ()
 	}
 }
 
-nframes_t
+framecnt_t
 AudioSource::available_peaks (double zoom_factor) const
 {
 	if (zoom_factor < _FPP) {
diff --git a/libs/ardour/crossfade.cc b/libs/ardour/crossfade.cc
index 0ca173570a..dc84352f4e 100644
--- a/libs/ardour/crossfade.cc
+++ b/libs/ardour/crossfade.cc
@@ -36,9 +36,9 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
-nframes_t Crossfade::_short_xfade_length = 0;
-Change Crossfade::ActiveChanged = new_change();
-Change Crossfade::FollowOverlapChanged = new_change();
+framecnt_t Crossfade::_short_xfade_length = 0;
+PropertyChange Crossfade::ActiveChanged = new_change();
+PropertyChange Crossfade::FollowOverlapChanged = new_change();
 
 /* XXX if and when we ever implement parallel processing of the process()
    callback, these will need to be handled on a per-thread basis.
@@ -48,7 +48,7 @@ Sample* Crossfade::crossfade_buffer_out = 0;
 Sample* Crossfade::crossfade_buffer_in = 0;
 
 void
-Crossfade::set_buffer_size (nframes_t sz)
+Crossfade::set_buffer_size (framecnt_t sz)
 {
 	delete [] crossfade_buffer_out;
 	crossfade_buffer_out = 0;
@@ -69,8 +69,8 @@ Crossfade::operator== (const Crossfade& other)
 }
 
 Crossfade::Crossfade (boost::shared_ptr<AudioRegion> in, boost::shared_ptr<AudioRegion> out,
-		      nframes_t length,
-		      nframes_t position,
+		      framecnt_t length,
+		      framepos_t position,
 		      AnchorPoint ap)
 	: AudioRegion (in->session(), position, length, in->name() + string ("<>") + out->name()),
 	  _fade_in (Evoral::Parameter(FadeInAutomation)), // linear (gain coefficient) => -inf..+6dB
@@ -162,9 +162,9 @@ Crossfade::Crossfade (const Playlist& playlist, XMLNode& node)
 }
 
 Crossfade::Crossfade (boost::shared_ptr<Crossfade> orig, boost::shared_ptr<AudioRegion> newin, boost::shared_ptr<AudioRegion> newout)
-	: AudioRegion (boost::dynamic_pointer_cast<const AudioRegion> (orig)),
-	  _fade_in (orig->_fade_in),
-	  _fade_out (orig->_fade_out)
+	: AudioRegion (boost::dynamic_pointer_cast<const AudioRegion> (orig), 0, true)
+	, _fade_in (orig->_fade_in)
+	, _fade_out (orig->_fade_out)
 {
 	_active           = orig->_active;
 	_in_update        = orig->_in_update;
@@ -267,32 +267,28 @@ Crossfade::initialize ()
 	layer_relation = (int32_t) (_in->layer() - _out->layer());
 }
 
-nframes_t
-Crossfade::read_raw_internal (Sample* /*buf*/, sframes_t /*start*/, nframes_t cnt, int /*channel*/) const
+framecnt_t
+Crossfade::read_raw_internal (Sample* buf, framecnt_t start, framecnt_t cnt, int channel) const
 {
-	// FIXME: Why is this disabled?
-#if 0
 	Sample* mixdown = new Sample[cnt];
 	float* gain = new float[cnt];
-	nframes_t ret;
-
-	ret = read_at (buf, mixdown, gain, start, cnt, chan_n, cnt);
+	framecnt_t ret;
+	
+	ret = read_at (buf, mixdown, gain, start, cnt, channel, cnt);
 
 	delete [] mixdown;
 	delete [] gain;
 
 	return ret;
-#endif
-	return cnt;
 }
 
-nframes_t
+framecnt_t
 Crossfade::read_at (Sample *buf, Sample *mixdown_buffer,
-		    float *gain_buffer, sframes_t start, nframes_t cnt, uint32_t chan_n,
-		    nframes_t read_frames, nframes_t skip_frames) const
+		    float *gain_buffer, framepos_t start, framecnt_t cnt, uint32_t chan_n,
+		    framecnt_t read_frames, framecnt_t skip_frames) const
 {
-	nframes_t offset;
-	nframes_t to_write;
+	frameoffset_t offset;
+	framecnt_t to_write;
 
 	if (!_active) {
 		return 0;
@@ -314,11 +310,11 @@ Crossfade::read_at (Sample *buf, Sample *mixdown_buffer,
 
 		start = _position;
 		buf += offset;
-		to_write = min (_length.val(), cnt);
+		to_write = min (_length.val(), (nframes64_t) cnt);
 
 	} else {
 
-		to_write = min (nframes_t(_length - (start - _position)), cnt);
+		to_write = min ((_length - (start - _position)), cnt);
 
 	}
 
@@ -346,7 +342,7 @@ Crossfade::read_at (Sample *buf, Sample *mixdown_buffer,
 	   position and length, and so we know precisely how much data they could return.
 	*/
 
-	for (nframes_t n = 0; n < to_write; ++n) {
+	for (framecnt_t n = 0; n < to_write; ++n) {
 		buf[n] = (crossfade_buffer_out[n] * fov[n]) + (crossfade_buffer_in[n] * fiv[n]);
 	}
 
@@ -357,9 +353,9 @@ Crossfade::read_at (Sample *buf, Sample *mixdown_buffer,
 }
 
 OverlapType
-Crossfade::coverage (nframes_t start, nframes_t end) const
+Crossfade::coverage (framepos_t start, framepos_t end) const
 {
-	nframes_t my_end = _position + _length;
+	framepos_t my_end = _position + _length;
 
 	if ((start >= _position) && (end <= my_end)) {
 		return OverlapInternal;
@@ -457,7 +453,7 @@ Crossfade::refresh ()
 bool
 Crossfade::update ()
 {
-	nframes_t newlen;
+	framecnt_t newlen;
 
 	if (_follow_overlap) {
 		newlen = _out->first_frame() + _out->length() - _in->first_frame();
@@ -503,7 +499,7 @@ Crossfade::compute (boost::shared_ptr<AudioRegion> a, boost::shared_ptr<AudioReg
 {
 	boost::shared_ptr<AudioRegion> top;
 	boost::shared_ptr<AudioRegion> bottom;
-	nframes_t short_xfade_length;
+	framecnt_t short_xfade_length;
 
 	short_xfade_length = _short_xfade_length;
 
@@ -679,11 +675,11 @@ Crossfade::get_state ()
 	node->add_property ("active", (_active ? "yes" : "no"));
 	node->add_property ("follow-overlap", (_follow_overlap ? "yes" : "no"));
 	node->add_property ("fixed", (_fixed ? "yes" : "no"));
-	snprintf (buf, sizeof(buf), "%" PRIu32, _length.val());
+	snprintf (buf, sizeof(buf), "%" PRId64, _length.val());
 	node->add_property ("length", buf);
 	snprintf (buf, sizeof(buf), "%" PRIu32, (uint32_t) _anchor_point);
 	node->add_property ("anchor-point", buf);
-	snprintf (buf, sizeof(buf), "%" PRIu32, (uint32_t) _position);
+	snprintf (buf, sizeof(buf), "%" PRId64, _position.val());
 	node->add_property ("position", buf);
 
 	child = node->add_child ("FadeIn");
@@ -693,7 +689,7 @@ Crossfade::get_state ()
 
 		pnode = new XMLNode ("point");
 
-		snprintf (buf, sizeof (buf), "%" PRIu32, (nframes_t) floor ((*ii)->when));
+		snprintf (buf, sizeof (buf), "%" PRId64, (framepos_t) floor ((*ii)->when));
 		pnode->add_property ("x", buf);
 		snprintf (buf, sizeof (buf), "%.12g", (*ii)->value);
 		pnode->add_property ("y", buf);
@@ -707,7 +703,7 @@ Crossfade::get_state ()
 
 		pnode = new XMLNode ("point");
 
-		snprintf (buf, sizeof (buf), "%" PRIu32, (nframes_t) floor ((*ii)->when));
+		snprintf (buf, sizeof (buf), "%" PRId64, (framepos_t) floor ((*ii)->when));
 		pnode->add_property ("x", buf);
 		snprintf (buf, sizeof (buf), "%.12g", (*ii)->value);
 		pnode->add_property ("y", buf);
@@ -726,14 +722,14 @@ Crossfade::set_state (const XMLNode& node, int /*version*/)
 	XMLNode* fo;
 	const XMLProperty* prop;
 	LocaleGuard lg (X_("POSIX"));
-	Change what_changed = Change (0);
-	nframes_t val;
+	PropertyChange what_changed = PropertyChange (0);
+	framepos_t val;
 
 	if ((prop = node.property ("position")) != 0) {
-		sscanf (prop->value().c_str(), "%" PRIu32, &val);
+		sscanf (prop->value().c_str(), "%" PRId64, &val);
 		if (val != _position) {
 			_position = val;
-			what_changed = Change (what_changed | PositionChanged);
+			what_changed = PropertyChange (what_changed | PositionChanged);
 		}
 	} else {
 		warning << _("old-style crossfade information - no position information") << endmsg;
@@ -744,7 +740,7 @@ Crossfade::set_state (const XMLNode& node, int /*version*/)
 		bool x = string_is_affirmative (prop->value());
 		if (x != _active) {
 			_active = x;
-			what_changed = Change (what_changed | ActiveChanged);
+			what_changed = PropertyChange (what_changed | ActiveChanged);
 		}
 	} else {
 		_active = true;
@@ -770,10 +766,10 @@ Crossfade::set_state (const XMLNode& node, int /*version*/)
 
 	if ((prop = node.property ("length")) != 0) {
 
-		sscanf (prop->value().c_str(), "%" PRIu32, &val);
+		sscanf (prop->value().c_str(), "%" PRId64, &val);
 		if (val != _length) {
-			_length = atol (prop->value().c_str());
-			what_changed = Change (what_changed | LengthChanged);
+			_length = val;
+			what_changed = PropertyChange (what_changed | LengthChanged);
 		}
 
 	} else {
@@ -804,11 +800,11 @@ Crossfade::set_state (const XMLNode& node, int /*version*/)
 
 	for (i = children.begin(); i != children.end(); ++i) {
 		if ((*i)->name() == "point") {
-			nframes_t x;
+			framepos_t x;
 			float y;
 
 			prop = (*i)->property ("x");
-			sscanf (prop->value().c_str(), "%" PRIu32, &x);
+			sscanf (prop->value().c_str(), "%" PRId64, &x);
 
 			prop = (*i)->property ("y");
 			sscanf (prop->value().c_str(), "%f", &y);
@@ -828,12 +824,12 @@ Crossfade::set_state (const XMLNode& node, int /*version*/)
 
 	for (i = children.begin(); i != children.end(); ++i) {
 		if ((*i)->name() == "point") {
-			nframes_t x;
+			framepos_t x;
 			float y;
 			XMLProperty* prop;
 
 			prop = (*i)->property ("x");
-			sscanf (prop->value().c_str(), "%" PRIu32, &x);
+			sscanf (prop->value().c_str(), "%" PRId64, &x);
 
 			prop = (*i)->property ("y");
 			sscanf (prop->value().c_str(), "%f", &y);
@@ -873,10 +869,10 @@ Crossfade::set_follow_overlap (bool yn)
 	StateChanged (FollowOverlapChanged);
 }
 
-nframes_t
-Crossfade::set_xfade_length (nframes_t len)
+framecnt_t
+Crossfade::set_xfade_length (framecnt_t len)
 {
-	nframes_t limit = 0;
+	framecnt_t limit = 0;
 
 	switch (_anchor_point) {
 	case StartOfIn:
@@ -909,7 +905,7 @@ Crossfade::set_xfade_length (nframes_t len)
 	return len;
 }
 
-nframes_t
+framecnt_t
 Crossfade::overlap_length () const
 {
 	if (_fixed) {
@@ -919,7 +915,7 @@ Crossfade::overlap_length () const
 }
 
 void
-Crossfade::set_short_xfade_length (nframes_t n)
+Crossfade::set_short_xfade_length (framecnt_t n)
 {
 	_short_xfade_length = n;
 }
diff --git a/libs/ardour/debug.cc b/libs/ardour/debug.cc
index 45f7e68434..48edc9a8d5 100644
--- a/libs/ardour/debug.cc
+++ b/libs/ardour/debug.cc
@@ -92,6 +92,8 @@ ARDOUR::parse_debug_options (const char* str)
 			bits |= ARDOUR::DEBUG::MidiIO;
 		} else if (strncasecmp (p, "midiclock", strlen (p)) == 0) {
 			bits |= ARDOUR::DEBUG::MidiClock;
+		} else if (strncasecmp (p, "properties", strlen (p)) == 0) {
+			bits |= ARDOUR::DEBUG::Properties;
 		}		
 
 		p = strtok_r (0, ",", &sp);
@@ -122,4 +124,5 @@ ARDOUR::list_debug_options ()
 	cerr << "\tMidiIO" << endl;
 	cerr << "\tLatencyCompensation" << endl;
 	cerr << "\tMidiClock" << endl;
+	cerr << "\tProperties" << endl;
 }
diff --git a/libs/ardour/diskstream.cc b/libs/ardour/diskstream.cc
index 264dd3e79f..6aee3a7572 100644
--- a/libs/ardour/diskstream.cc
+++ b/libs/ardour/diskstream.cc
@@ -361,7 +361,7 @@ Diskstream::use_playlist (boost::shared_ptr<Playlist> playlist)
 }
 
 void
-Diskstream::playlist_changed (Change)
+Diskstream::playlist_changed (PropertyChange)
 {
 	playlist_modified ();
 }
@@ -426,7 +426,7 @@ Diskstream::remove_region_from_last_capture (boost::weak_ptr<Region> wregion)
 }
 
 void
-Diskstream::playlist_ranges_moved (list< Evoral::RangeMove<nframes_t> > const & movements_frames)
+Diskstream::playlist_ranges_moved (list< Evoral::RangeMove<framepos_t> > const & movements_frames)
 {
 	if (!_route || Config->get_automation_follows_regions () == false) {
 		return;
@@ -434,7 +434,7 @@ Diskstream::playlist_ranges_moved (list< Evoral::RangeMove<nframes_t> > const &
 
 	list< Evoral::RangeMove<double> > movements;
 
-	for (list< Evoral::RangeMove<nframes_t> >::const_iterator i = movements_frames.begin();
+	for (list< Evoral::RangeMove<framepos_t> >::const_iterator i = movements_frames.begin();
 	     i != movements_frames.end();
 	     ++i) {
 
@@ -458,7 +458,7 @@ Diskstream::playlist_ranges_moved (list< Evoral::RangeMove<nframes_t> > const &
 }
 
 void
-Diskstream::move_processor_automation (boost::weak_ptr<Processor> p, list< Evoral::RangeMove<nframes_t> > const & movements_frames)
+Diskstream::move_processor_automation (boost::weak_ptr<Processor> p, list< Evoral::RangeMove<framepos_t> > const & movements_frames)
 {
 	boost::shared_ptr<Processor> processor (p.lock ());
 	if (!processor) {
@@ -466,7 +466,7 @@ Diskstream::move_processor_automation (boost::weak_ptr<Processor> p, list< Evora
 	}
 
 	list< Evoral::RangeMove<double> > movements;
-	for (list< Evoral::RangeMove<nframes_t> >::const_iterator i = movements_frames.begin();
+	for (list< Evoral::RangeMove<framepos_t> >::const_iterator i = movements_frames.begin();
 		   i != movements_frames.end(); ++i) {
 		movements.push_back(Evoral::RangeMove<double>(i->from, i->length, i->to));
 	}
diff --git a/libs/ardour/enums.cc b/libs/ardour/enums.cc
index 9a512fe708..baf8f7326d 100644
--- a/libs/ardour/enums.cc
+++ b/libs/ardour/enums.cc
@@ -33,7 +33,6 @@
 #include "ardour/midi_track.h"
 #include "ardour/mute_master.h"
 #include "ardour/panner.h"
-#include "ardour/region_command.h"
 #include "ardour/route_group.h"
 #include "ardour/session.h"
 #include "ardour/track.h"
@@ -94,9 +93,6 @@ setup_enum_writer ()
 	Source::Flag _Source_Flag;
 	Diskstream::Flag _Diskstream_Flag;
 	Location::Flags _Location_Flags;
-	RouteGroup::Flag _RouteGroup_Flag;
-	RouteGroup::Property _RouteGroup_Property;
-	Region::Flag _Region_Flag;
 	Region::PositionLockStyle _Region_PositionLockStyle;
 	Track::FreezeState _Track_FreezeState;
 	AutomationList::InterpolationStyle _AutomationList_InterpolationStyle;
@@ -122,7 +118,6 @@ setup_enum_writer ()
 	Session::PostTransportWork _Session_PostTransportWork;
 	Session::SlaveState _Session_SlaveState;
 	MTC_Status _MIDI_MTC_Status;
-	RegionCommand::Property _RegionCommandProperty;
 
 #define REGISTER(e) enum_writer.register_distinct (typeid(e).name(), i, s); i.clear(); s.clear()
 #define REGISTER_BITS(e) enum_writer.register_bits (typeid(e).name(), i, s); i.clear(); s.clear()
@@ -410,44 +405,10 @@ setup_enum_writer ()
 	REGISTER_CLASS_ENUM (Location, IsStart);
 	REGISTER_BITS (_Location_Flags);
 
-	REGISTER_CLASS_ENUM (RouteGroup, Relative);
-	REGISTER_CLASS_ENUM (RouteGroup, Active);
-	REGISTER_CLASS_ENUM (RouteGroup, Hidden);
-	REGISTER_BITS (_RouteGroup_Flag);
-
-	REGISTER_CLASS_ENUM (RouteGroup, Gain);
-	REGISTER_CLASS_ENUM (RouteGroup, Mute);
-	REGISTER_CLASS_ENUM (RouteGroup, Solo);
-	REGISTER_CLASS_ENUM (RouteGroup, RecEnable);
-	REGISTER_CLASS_ENUM (RouteGroup, Select);
-	REGISTER_CLASS_ENUM (RouteGroup, Edit);
-	REGISTER_BITS (_RouteGroup_Property);
-
 	REGISTER_CLASS_ENUM (Panner, SameDirection);
 	REGISTER_CLASS_ENUM (Panner, OppositeDirection);
 	REGISTER (_Panner_LinkDirection);
 
-	REGISTER_CLASS_ENUM (Region, Muted);
-	REGISTER_CLASS_ENUM (Region, Opaque);
-	REGISTER_CLASS_ENUM (Region, EnvelopeActive);
-	REGISTER_CLASS_ENUM (Region, DefaultFadeIn);
-	REGISTER_CLASS_ENUM (Region, DefaultFadeOut);
-	REGISTER_CLASS_ENUM (Region, Locked);
-	REGISTER_CLASS_ENUM (Region, PositionLocked);
-	REGISTER_CLASS_ENUM (Region, Automatic);
-	REGISTER_CLASS_ENUM (Region, WholeFile);
-	REGISTER_CLASS_ENUM (Region, FadeIn);
-	REGISTER_CLASS_ENUM (Region, FadeOut);
-	REGISTER_CLASS_ENUM (Region, Copied);
-	REGISTER_CLASS_ENUM (Region, Import);
-	REGISTER_CLASS_ENUM (Region, External);
-	REGISTER_CLASS_ENUM (Region, SyncMarked);
-	REGISTER_CLASS_ENUM (Region, LeftOfSplit);
-	REGISTER_CLASS_ENUM (Region, RightOfSplit);
-	REGISTER_CLASS_ENUM (Region, Hidden);
-	REGISTER_CLASS_ENUM (Region, DoNotSendPropertyChanges);
-	REGISTER_BITS (_Region_Flag);
-
 	REGISTER_CLASS_ENUM (Region, AudioTime);
 	REGISTER_CLASS_ENUM (Region, MusicTime);
 	REGISTER_BITS (_Region_PositionLockStyle);
@@ -584,32 +545,6 @@ setup_enum_writer ()
 	REGISTER_ENUM(Legato);
 	REGISTER_ENUM(Groove);
 	REGISTER(_QuantizeType);
-
-	REGISTER_CLASS_ENUM (RegionCommand, Name);
-	REGISTER_CLASS_ENUM (RegionCommand, PositionLockStyle);
-	REGISTER_CLASS_ENUM (RegionCommand, Length);
-	REGISTER_CLASS_ENUM (RegionCommand, Start);
-	REGISTER_CLASS_ENUM (RegionCommand, Position);
-	REGISTER_CLASS_ENUM (RegionCommand, PositionOnTop);
-	REGISTER_CLASS_ENUM (RegionCommand, Layer);
-	REGISTER_CLASS_ENUM (RegionCommand, SyncPosition);
-	REGISTER_CLASS_ENUM (RegionCommand, Hidden);
-	REGISTER_CLASS_ENUM (RegionCommand, Muted);
-	REGISTER_CLASS_ENUM (RegionCommand, Opaque);
-	REGISTER_CLASS_ENUM (RegionCommand, Locked);
-	REGISTER_CLASS_ENUM (RegionCommand, PositionLocked);
-	REGISTER_CLASS_ENUM (RegionCommand, ScaleAmplitude);
-	REGISTER_CLASS_ENUM (RegionCommand, FadeInActive);
-	REGISTER_CLASS_ENUM (RegionCommand, FadeInShape);
-	REGISTER_CLASS_ENUM (RegionCommand, FadeInLength);
-	REGISTER_CLASS_ENUM (RegionCommand, FadeIn);
-	REGISTER_CLASS_ENUM (RegionCommand, FadeOutActive);
-	REGISTER_CLASS_ENUM (RegionCommand, FadeOutShape);
-	REGISTER_CLASS_ENUM (RegionCommand, FadeOutLength);
-	REGISTER_CLASS_ENUM (RegionCommand, FadeOut);
-	REGISTER_CLASS_ENUM (RegionCommand, EnvelopActive);
-	REGISTER_CLASS_ENUM (RegionCommand, DefaultEnvelope);
-	REGISTER(_RegionCommandProperty);
 }
 
 } /* namespace ARDOUR */
diff --git a/libs/ardour/filter.cc b/libs/ardour/filter.cc
index eab27b4ce0..2ff93316f3 100644
--- a/libs/ardour/filter.cc
+++ b/libs/ardour/filter.cc
@@ -120,9 +120,15 @@ Filter::finish (boost::shared_ptr<Region> region, SourceList& nsrcs, string regi
 	}
 	results.clear ();
 
-	boost::shared_ptr<Region> r = RegionFactory::create (nsrcs, 0, region->length(), region_name, 0,
-							     Region::Flag (Region::WholeFile|Region::DefaultFlags));
-	r->set_position (region->position(), 0);
+	PropertyList plist;
+	
+	plist.add (Properties::start, 0);
+	plist.add (Properties::length, region->length());
+	plist.add (Properties::name, region_name);
+	plist.add (Properties::whole_file, true);
+	plist.add (Properties::position, region->position());
+
+	boost::shared_ptr<Region> r = RegionFactory::create (nsrcs, plist);
 
 	boost::shared_ptr<AudioRegion> audio_region = boost::dynamic_pointer_cast<AudioRegion> (region);
 	boost::shared_ptr<AudioRegion> audio_r = boost::dynamic_pointer_cast<AudioRegion> (r);
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index 3f3c35f739..f117e6d063 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -62,6 +62,7 @@
 #include "ardour/ardour.h"
 #include "ardour/audio_library.h"
 #include "ardour/audioengine.h"
+#include "ardour/audioregion.h"
 #include "ardour/audiosource.h"
 #include "ardour/control_protocol_manager.h"
 #include "ardour/debug.h"
@@ -69,7 +70,9 @@
 #include "ardour/mix.h"
 #include "ardour/plugin_manager.h"
 #include "ardour/profile.h"
+#include "ardour/region.h"
 #include "ardour/rc_configuration.h"
+#include "ardour/route_group.h"
 #include "ardour/runtime_functions.h"
 #include "ardour/session.h"
 #include "ardour/session_event.h"
@@ -99,12 +102,11 @@ MIDI::Port *ARDOUR::default_mtc_port = 0;
 MIDI::Port *ARDOUR::default_midi_port = 0;
 MIDI::Port *ARDOUR::default_midi_clock_port = 0;
 
-PBD::Change ARDOUR::StartChanged = PBD::new_change ();
-PBD::Change ARDOUR::LengthChanged = PBD::new_change ();
-PBD::Change ARDOUR::PositionChanged = PBD::new_change ();
-PBD::Change ARDOUR::NameChanged = PBD::new_change ();
-PBD::Change ARDOUR::BoundsChanged = Change (0); // see init(), below
-PBD::Change ARDOUR::FlagsChanged = PBD::new_change ();
+PropertyChange ARDOUR::StartChanged = PBD::new_change ();
+PropertyChange ARDOUR::LengthChanged = PBD::new_change ();
+PropertyChange ARDOUR::PositionChanged = PBD::new_change ();
+PropertyChange ARDOUR::NameChanged = PBD::new_change ();
+PropertyChange ARDOUR::BoundsChanged = PropertyChange (0); // see init(), below
 
 compute_peak_t          ARDOUR::compute_peak = 0;
 find_peaks_t            ARDOUR::find_peaks = 0;
@@ -301,6 +303,10 @@ ARDOUR::init (bool use_vst, bool try_optimization)
 	PBD::ID::init ();
 	SessionEvent::init_event_pool ();
 
+	SessionObject::make_property_quarks ();
+	Region::make_property_quarks ();
+	AudioRegion::make_property_quarks ();
+	RouteGroup::make_property_quarks ();
 
 	/* provide a state version for the few cases that need it and are not
 	   driven by reading state from disk (e.g. undo/redo)
@@ -361,7 +367,7 @@ ARDOUR::init (bool use_vst, bool try_optimization)
 	/* singleton - first object is "it" */
 	new PluginManager ();
 
-	BoundsChanged = Change (StartChanged|PositionChanged|LengthChanged);
+	BoundsChanged = PropertyChange (StartChanged|PositionChanged|LengthChanged);
 
 	return 0;
 }
diff --git a/libs/ardour/midi_diskstream.cc b/libs/ardour/midi_diskstream.cc
index 11fec341b2..4f7d6364b0 100644
--- a/libs/ardour/midi_diskstream.cc
+++ b/libs/ardour/midi_diskstream.cc
@@ -373,7 +373,7 @@ trace_midi (ostream& o, MIDI::byte *msg, size_t len)
 		o << trace_prefix
 		   << "Channel "
 		   << (msg[0]&0xF)+1
-		   <<  " Program Change ProgNum "
+		   <<  " Program PropertyChange ProgNum "
 		   << (int) msg[1]
 		   << endl;
 		break;
@@ -985,9 +985,16 @@ MidiDiskstream::transport_stopped (struct tm& /*when*/, time_t /*twhen*/, bool a
 		   */
 
 		try {
-			boost::shared_ptr<Region> rx (RegionFactory::create (srcs, 0,
-					total_capture, whole_file_region_name, 0,
-					Region::Flag (Region::DefaultFlags|Region::Automatic|Region::WholeFile)));
+			PropertyList plist;
+
+			plist.add (Properties::name, whole_file_region_name);
+			plist.add (Properties::whole_file, true);
+			plist.add (Properties::automatic, true);
+			plist.add (Properties::start, 0);
+			plist.add (Properties::length, total_capture);
+			plist.add (Properties::layer, 0);
+				   
+			boost::shared_ptr<Region> rx (RegionFactory::create (srcs, plist));
 
 			region = boost::dynamic_pointer_cast<MidiRegion> (rx);
 			region->special_set_position (capture_info.front()->start);
@@ -1015,7 +1022,13 @@ MidiDiskstream::transport_stopped (struct tm& /*when*/, time_t /*twhen*/, bool a
 			// cerr << _name << ": based on ci of " << (*ci)->start << " for " << (*ci)->frames << " add a region\n";
 
 			try {
-				boost::shared_ptr<Region> rx (RegionFactory::create (srcs, buffer_position, (*ci)->frames, region_name));
+				PropertyList plist;
+				
+				plist.add (Properties::start, buffer_position);
+				plist.add (Properties::length, (*ci)->frames);
+				plist.add (Properties::name, region_name);
+				
+				boost::shared_ptr<Region> rx (RegionFactory::create (srcs, plist));
 				region = boost::dynamic_pointer_cast<MidiRegion> (rx);
 			}
 
diff --git a/libs/ardour/midi_playlist.cc b/libs/ardour/midi_playlist.cc
index e5c2e996f8..cafbcc9e93 100644
--- a/libs/ardour/midi_playlist.cc
+++ b/libs/ardour/midi_playlist.cc
@@ -415,7 +415,7 @@ MidiPlaylist::contained_automation()
 
 
 bool
-MidiPlaylist::region_changed (PBD::Change what_changed, boost::shared_ptr<Region> region)
+MidiPlaylist::region_changed (PBD::PropertyChange what_changed, boost::shared_ptr<Region> region)
 {
 	if (in_flush || in_set_state) {
 		return false;
@@ -423,7 +423,7 @@ MidiPlaylist::region_changed (PBD::Change what_changed, boost::shared_ptr<Region
 
 	// Feeling rather uninterested today, but thanks for the heads up anyway!
 
-	PBD::Change our_interests = PBD::Change (/*MidiRegion::FadeInChanged|
+	PBD::PropertyChange our_interests = PBD::PropertyChange (/*MidiRegion::FadeInChanged|
 	                               MidiRegion::FadeOutChanged|
 	                               MidiRegion::FadeInActiveChanged|
 	                               MidiRegion::FadeOutActiveChanged|
diff --git a/libs/ardour/midi_region.cc b/libs/ardour/midi_region.cc
index 0497abdcbb..f166dafda8 100644
--- a/libs/ardour/midi_region.cc
+++ b/libs/ardour/midi_region.cc
@@ -48,24 +48,16 @@ using namespace ARDOUR;
 using namespace PBD;
 
 /** Basic MidiRegion constructor (one channel) */
-MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src, nframes_t start, nframes_t length)
-	: Region (src, start, length, PBD::basename_nosuffix(src->name()), DataType::MIDI, 0,  Region::Flag(Region::DefaultFlags|Region::External))
-{
-	assert(_name.val().find("/") == string::npos);
-	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
-}
-
-/* Basic MidiRegion constructor (one channel) */
-MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src, nframes_t start, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: Region (src, start, length, name, DataType::MIDI, layer, flags)
+MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src)
+	: Region (src)
 {
 	assert(_name.val().find("/") == string::npos);
 	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
 }
 
 /* Basic MidiRegion constructor (many channels) */
-MidiRegion::MidiRegion (const SourceList& srcs, nframes_t start, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: Region (srcs, start, length, name, DataType::MIDI, layer, flags)
+MidiRegion::MidiRegion (const SourceList& srcs)
+	: Region (srcs)
 {
 	assert(_name.val().find("/") == string::npos);
 	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
@@ -73,15 +65,8 @@ MidiRegion::MidiRegion (const SourceList& srcs, nframes_t start, nframes_t lengt
 
 
 /** Create a new MidiRegion, that is part of an existing one */
-MidiRegion::MidiRegion (boost::shared_ptr<const MidiRegion> other, nframes_t offset, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: Region (other, offset, length, name, layer, flags)
-{
-	assert(_name.val().find("/") == string::npos);
-	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
-}
-
-MidiRegion::MidiRegion (boost::shared_ptr<const MidiRegion> other)
-	: Region (other)
+MidiRegion::MidiRegion (boost::shared_ptr<const MidiRegion> other, frameoffset_t offset, bool offset_relative)
+	: Region (other, offset, offset_relative)
 {
 	assert(_name.val().find("/") == string::npos);
 	midi_source(0)->Switched.connect_same_thread (*this, boost::bind (&MidiRegion::switch_source, this, _1));
@@ -116,7 +101,7 @@ MidiRegion::~MidiRegion ()
 }
 
 void
-MidiRegion::set_position_internal (nframes_t pos, bool allow_bbt_recompute)
+MidiRegion::set_position_internal (framepos_t pos, bool allow_bbt_recompute)
 {
 	BeatsFramesConverter old_converter(_session.tempo_map(), _position - _start);
 	double length_beats = old_converter.from(_length);
@@ -128,25 +113,25 @@ MidiRegion::set_position_internal (nframes_t pos, bool allow_bbt_recompute)
 	set_length(new_converter.to(length_beats), 0);
 }
 
-nframes_t
-MidiRegion::read_at (Evoral::EventSink<nframes_t>& out, sframes_t position, nframes_t dur, uint32_t chan_n, NoteMode mode, MidiStateTracker* tracker) const
+framecnt_t
+MidiRegion::read_at (Evoral::EventSink<nframes_t>& out, framepos_t position, framecnt_t dur, uint32_t chan_n, NoteMode mode, MidiStateTracker* tracker) const
 {
 	return _read_at (_sources, out, position, dur, chan_n, mode, tracker);
 }
 
-nframes_t
-MidiRegion::master_read_at (MidiRingBuffer<nframes_t>& out, sframes_t position, nframes_t dur, uint32_t chan_n, NoteMode mode) const
+framecnt_t
+MidiRegion::master_read_at (MidiRingBuffer<nframes_t>& out, framepos_t position, framecnt_t dur, uint32_t chan_n, NoteMode mode) const
 {
 	return _read_at (_master_sources, out, position, dur, chan_n, mode); /* no tracker */
 }
 
-nframes_t
-MidiRegion::_read_at (const SourceList& /*srcs*/, Evoral::EventSink<nframes_t>& dst, sframes_t position, nframes_t dur, uint32_t chan_n, 
+framecnt_t
+MidiRegion::_read_at (const SourceList& /*srcs*/, Evoral::EventSink<nframes_t>& dst, framepos_t position, framecnt_t dur, uint32_t chan_n, 
 		      NoteMode mode, MidiStateTracker* tracker) const
 {
-	nframes_t internal_offset = 0;
-	nframes_t src_offset      = 0;
-	nframes_t to_read         = 0;
+	frameoffset_t internal_offset = 0;
+	frameoffset_t src_offset      = 0;
+	framecnt_t to_read         = 0;
 
 	/* precondition: caller has verified that we cover the desired section */
 
@@ -178,8 +163,8 @@ MidiRegion::_read_at (const SourceList& /*srcs*/, Evoral::EventSink<nframes_t>&
 	boost::shared_ptr<MidiSource> src = midi_source(chan_n);
 	src->set_note_mode(mode);
 
-	nframes_t output_buffer_position = 0;
-	nframes_t negative_output_buffer_position = 0;
+	framepos_t output_buffer_position = 0;
+	framepos_t negative_output_buffer_position = 0;
 	if (_position >= _start) {
 		// handle resizing of beginnings of regions correctly
 		output_buffer_position = _position - _start;
@@ -244,49 +229,8 @@ MidiRegion::state (bool full)
 }
 
 int
-MidiRegion::set_live_state (const XMLNode& node, int version, Change& what_changed, bool send)
-{
-	const XMLProperty *prop;
-	LocaleGuard lg (X_("POSIX"));
-
-	Region::set_live_state (node, version, what_changed, false);
-
-	uint32_t old_flags = _flags;
-
-	if ((prop = node.property ("flags")) != 0) {
-		_flags = Flag (string_2_enum (prop->value(), _flags));
-
-		//_flags = Flag (strtol (prop->value().c_str(), (char **) 0, 16));
-
-		_flags = Flag (_flags & ~Region::LeftOfSplit);
-		_flags = Flag (_flags & ~Region::RightOfSplit);
-	}
-
-	if ((old_flags ^ _flags) & Muted) {
-		what_changed = Change (what_changed|MuteChanged);
-	}
-	if ((old_flags ^ _flags) & Opaque) {
-		what_changed = Change (what_changed|OpacityChanged);
-	}
-	if ((old_flags ^ _flags) & Locked) {
-		what_changed = Change (what_changed|LockChanged);
-	}
-
-	if (send) {
-		send_change (what_changed);
-	}
-
-	return 0;
-}
-
-int
 MidiRegion::set_state (const XMLNode& node, int version)
 {
-	/* Region::set_state() calls the virtual set_live_state(),
-	   which will get us back to AudioRegion::set_live_state()
-	   to handle the relevant stuff.
-	*/
-
 	return Region::set_state (node, version);
 }
 
diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index 39bd5695b4..9d909d0fa6 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -148,14 +148,14 @@ Playlist::Playlist (boost::shared_ptr<const Playlist> other, string namestr, boo
 	freeze_length = other->freeze_length;
 }
 
-Playlist::Playlist (boost::shared_ptr<const Playlist> other, nframes_t start, nframes_t cnt, string str, bool hide)
+Playlist::Playlist (boost::shared_ptr<const Playlist> other, framepos_t start, framecnt_t cnt, string str, bool hide)
 	: SessionObject(other->_session, str)
 	, _type(other->_type)
 	, _orig_diskstream_id(other->_orig_diskstream_id)
 {
 	RegionLock rlock2 (const_cast<Playlist*> (other.get()));
 
-	nframes_t end = start + cnt - 1;
+	framepos_t end = start + cnt - 1;
 
 	init (hide);
 
@@ -165,9 +165,9 @@ Playlist::Playlist (boost::shared_ptr<const Playlist> other, nframes_t start, nf
 
 		boost::shared_ptr<Region> region;
 		boost::shared_ptr<Region> new_region;
-		nframes_t offset = 0;
-		nframes_t position = 0;
-		nframes_t len = 0;
+		frameoffset_t offset = 0;
+		framepos_t position = 0;
+		framecnt_t len = 0;
 		string    new_name;
 		OverlapType overlap;
 
@@ -206,7 +206,14 @@ Playlist::Playlist (boost::shared_ptr<const Playlist> other, nframes_t start, nf
 
 		_session.region_name (new_name, region->name(), false);
 
-		new_region = RegionFactory::RegionFactory::create (region, offset, len, new_name, region->layer(), region->flags());
+		PropertyList plist; 
+
+		plist.add (Properties::start, offset);
+		plist.add (Properties::length, len);
+		plist.add (Properties::name, new_name);
+		plist.add (Properties::layer, region->layer());
+
+		new_region = RegionFactory::RegionFactory::create (region, plist);
 
 		add_region_internal (new_region, position);
 	}
@@ -391,7 +398,7 @@ Playlist::notify_region_removed (boost::shared_ptr<Region> r)
 void
 Playlist::notify_region_moved (boost::shared_ptr<Region> r)
 {
-	Evoral::RangeMove<nframes_t> const move (r->last_position (), r->length (), r->position ());
+	Evoral::RangeMove<framepos_t> const move (r->last_position (), r->length (), r->position ());
 
 	if (holding_state ()) {
 
@@ -399,7 +406,7 @@ Playlist::notify_region_moved (boost::shared_ptr<Region> r)
 
 	} else {
 
-		list< Evoral::RangeMove<nframes_t> > m;
+		list< Evoral::RangeMove<framepos_t> > m;
 		m.push_back (move);
 		RangesMoved (m);
 	}
@@ -450,7 +457,7 @@ Playlist::flush_notifications ()
 	set<boost::shared_ptr<Region> >::iterator s;
 	uint32_t regions_changed = false;
 	bool check_length = false;
-	nframes64_t old_length = 0;
+	framecnt_t old_length = 0;
 
 	if (in_flush) {
 		return;
@@ -547,17 +554,17 @@ Playlist::clear_pending ()
  *************************************************************/
 
 void
-Playlist::add_region (boost::shared_ptr<Region> region, nframes_t position, float times, bool auto_partition)
+Playlist::add_region (boost::shared_ptr<Region> region, framepos_t position, float times, bool auto_partition)
 {
 	RegionLock rlock (this);
 	times = fabs (times);
 
 	int itimes = (int) floor (times);
 
-	nframes_t pos = position;
+	framepos_t pos = position;
 
 	if (times == 1 && auto_partition){
-		partition(pos, (nframes_t) (pos + region->length()), true);
+		partition(pos, (pos + region->length()), true);
 	}
 
 	if (itimes >= 1) {
@@ -577,14 +584,24 @@ Playlist::add_region (boost::shared_ptr<Region> region, nframes_t position, floa
 		pos += region->length();
 	}
 
-	nframes_t length = 0;
+	framecnt_t length = 0;
 
 	if (floor (times) != times) {
-		length = (nframes_t) floor (region->length() * (times - floor (times)));
+		length = (framecnt_t) floor (region->length() * (times - floor (times)));
 		string name;
 		_session.region_name (name, region->name(), false);
-		boost::shared_ptr<Region> sub = RegionFactory::create (region, 0, length, name, region->layer(), region->flags());
-		add_region_internal (sub, pos);
+
+		{
+			PropertyList plist;
+			
+			plist.add (Properties::start, 0);
+			plist.add (Properties::length, length);
+			plist.add (Properties::name, name);
+			plist.add (Properties::layer, region->layer());
+
+			boost::shared_ptr<Region> sub = RegionFactory::create (region, plist);
+			add_region_internal (sub, pos);
+		}
 	}
 
 	possibly_splice_unlocked (position, (pos + length) - position, boost::shared_ptr<Region>());
@@ -603,7 +620,7 @@ Playlist::set_region_ownership ()
 }
 
 bool
-Playlist::add_region_internal (boost::shared_ptr<Region> region, nframes_t position)
+Playlist::add_region_internal (boost::shared_ptr<Region> region, framepos_t position)
 {
 	if (region->data_type() != _type){
 		return false;
@@ -611,7 +628,7 @@ Playlist::add_region_internal (boost::shared_ptr<Region> region, nframes_t posit
 
 	RegionSortByPosition cmp;
 
-	nframes_t old_length = 0;
+	framecnt_t old_length = 0;
 
 	if (!holding_state()) {
 		 old_length = _get_maximum_extent();
@@ -655,7 +672,7 @@ Playlist::add_region_internal (boost::shared_ptr<Region> region, nframes_t posit
 }
 
 void
-Playlist::replace_region (boost::shared_ptr<Region> old, boost::shared_ptr<Region> newr, nframes_t pos)
+Playlist::replace_region (boost::shared_ptr<Region> old, boost::shared_ptr<Region> newr, framepos_t pos)
 {
 	RegionLock rlock (this);
 
@@ -667,7 +684,7 @@ Playlist::replace_region (boost::shared_ptr<Region> old, boost::shared_ptr<Regio
 
 	_splicing = old_sp;
 
-	possibly_splice_unlocked (pos, (nframes64_t) old->length() - (nframes64_t) newr->length());
+	possibly_splice_unlocked (pos, old->length() - newr->length());
 }
 
 void
@@ -681,7 +698,7 @@ int
 Playlist::remove_region_internal (boost::shared_ptr<Region> region)
 {
 	RegionList::iterator i;
-	nframes_t old_length = 0;
+	framecnt_t old_length = 0;
 	int ret = -1;
 
 	if (!holding_state()) {
@@ -698,8 +715,8 @@ Playlist::remove_region_internal (boost::shared_ptr<Region> region)
 	for (i = regions.begin(); i != regions.end(); ++i) {
 		if (*i == region) {
 
-			nframes_t pos = (*i)->position();
-			nframes64_t distance = (*i)->length();
+			framepos_t pos = (*i)->position();
+			framecnt_t distance = (*i)->length();
 
 			regions.erase (i);
 
@@ -755,7 +772,7 @@ Playlist::get_region_list_equivalent_regions (boost::shared_ptr<Region> other, v
 }
 
 void
-Playlist::partition (nframes_t start, nframes_t end, bool cut)
+Playlist::partition (framepos_t start, framepos_t end, bool cut)
 {
 	RegionList thawlist;
 
@@ -767,7 +784,7 @@ Playlist::partition (nframes_t start, nframes_t end, bool cut)
 }
 
 void
-Playlist::partition_internal (nframes_t start, nframes_t end, bool cutting, RegionList& thawlist)
+Playlist::partition_internal (framepos_t start, framepos_t end, bool cutting, RegionList& thawlist)
 {
 	RegionList new_regions;
 
@@ -779,7 +796,7 @@ Playlist::partition_internal (nframes_t start, nframes_t end, bool cutting, Regi
 		string new_name;
 		RegionList::iterator tmp;
 		OverlapType overlap;
-		nframes_t pos1, pos2, pos3, pos4;
+		framepos_t pos1, pos2, pos3, pos4;
 
 		in_partition = true;
 
@@ -843,8 +860,18 @@ Playlist::partition_internal (nframes_t start, nframes_t end, bool cutting, Regi
 					/* "middle" ++++++ */
 
 					_session.region_name (new_name, current->name(), false);
-					region = RegionFactory::create (current, pos2 - pos1, pos3 - pos2, new_name,
-									regions.size(), Region::Flag(current->flags()|Region::Automatic|Region::LeftOfSplit|Region::RightOfSplit));
+
+					PropertyList plist;
+					
+					plist.add (Properties::start, pos2 - pos1);
+					plist.add (Properties::length, pos3 - pos2);
+					plist.add (Properties::name, new_name);
+					plist.add (Properties::layer, regions.size());
+					plist.add (Properties::automatic, true);
+					plist.add (Properties::left_of_split, true);
+					plist.add (Properties::right_of_split, true);
+
+					region = RegionFactory::create (current, plist);
 					add_region_internal (region, start);
 					new_regions.push_back (region);
 				}
@@ -852,8 +879,17 @@ Playlist::partition_internal (nframes_t start, nframes_t end, bool cutting, Regi
 				/* "end" ====== */
 
 				_session.region_name (new_name, current->name(), false);
-				region = RegionFactory::create (current, pos3 - pos1, pos4 - pos3, new_name,
-								regions.size(), Region::Flag(current->flags()|Region::Automatic|Region::RightOfSplit));
+
+				PropertyList plist;
+				
+				plist.add (Properties::start, pos3 - pos1);
+				plist.add (Properties::length, pos4 - pos3);
+				plist.add (Properties::name, new_name);
+				plist.add (Properties::layer, regions.size());
+				plist.add (Properties::automatic, true);
+				plist.add (Properties::right_of_split, true);
+				
+				region = RegionFactory::create (current, plist);
 
 				add_region_internal (region, end);
 				new_regions.push_back (region);
@@ -881,8 +917,17 @@ Playlist::partition_internal (nframes_t start, nframes_t end, bool cutting, Regi
 					/* end +++++ */
 
 					_session.region_name (new_name, current->name(), false);
-					region = RegionFactory::create (current, pos2 - pos1, pos4 - pos2, new_name, (layer_t) regions.size(),
-									Region::Flag(current->flags()|Region::Automatic|Region::LeftOfSplit));
+					
+					PropertyList plist;
+					
+					plist.add (Properties::start, pos2 - pos1);
+					plist.add (Properties::length, pos4 - pos2);
+					plist.add (Properties::name, new_name);
+					plist.add (Properties::layer, regions.size());
+					plist.add (Properties::automatic, true);
+					plist.add (Properties::left_of_split, true);
+
+					region = RegionFactory::create (current, plist);
 
 					add_region_internal (region, start);
 					new_regions.push_back (region);
@@ -915,8 +960,17 @@ Playlist::partition_internal (nframes_t start, nframes_t end, bool cutting, Regi
 				if (!cutting) {
 					/* front **** */
 					_session.region_name (new_name, current->name(), false);
-					region = RegionFactory::create (current, 0, pos3 - pos1, new_name,
-									regions.size(), Region::Flag(current->flags()|Region::Automatic|Region::RightOfSplit));
+
+					PropertyList plist;
+					
+					plist.add (Properties::start, 0);
+					plist.add (Properties::length, pos3 - pos1);
+					plist.add (Properties::name, new_name);
+					plist.add (Properties::layer, regions.size());
+					plist.add (Properties::automatic, true);
+					plist.add (Properties::right_of_split, true);
+
+					region = RegionFactory::create (current, plist);
 
 					add_region_internal (region, pos1);
 					new_regions.push_back (region);
@@ -962,11 +1016,11 @@ Playlist::partition_internal (nframes_t start, nframes_t end, bool cutting, Regi
 }
 
 boost::shared_ptr<Playlist>
-Playlist::cut_copy (boost::shared_ptr<Playlist> (Playlist::*pmf)(nframes_t, nframes_t,bool), list<AudioRange>& ranges, bool result_is_hidden)
+Playlist::cut_copy (boost::shared_ptr<Playlist> (Playlist::*pmf)(framepos_t, framecnt_t,bool), list<AudioRange>& ranges, bool result_is_hidden)
 {
 	boost::shared_ptr<Playlist> ret;
 	boost::shared_ptr<Playlist> pl;
-	nframes_t start;
+	framepos_t start;
 
 	if (ranges.empty()) {
 		return boost::shared_ptr<Playlist>();
@@ -997,19 +1051,19 @@ Playlist::cut_copy (boost::shared_ptr<Playlist> (Playlist::*pmf)(nframes_t, nfra
 boost::shared_ptr<Playlist>
 Playlist::cut (list<AudioRange>& ranges, bool result_is_hidden)
 {
-	boost::shared_ptr<Playlist> (Playlist::*pmf)(nframes_t,nframes_t,bool) = &Playlist::cut;
+	boost::shared_ptr<Playlist> (Playlist::*pmf)(framepos_t,framecnt_t,bool) = &Playlist::cut;
 	return cut_copy (pmf, ranges, result_is_hidden);
 }
 
 boost::shared_ptr<Playlist>
 Playlist::copy (list<AudioRange>& ranges, bool result_is_hidden)
 {
-	boost::shared_ptr<Playlist> (Playlist::*pmf)(nframes_t,nframes_t,bool) = &Playlist::copy;
+	boost::shared_ptr<Playlist> (Playlist::*pmf)(framepos_t,framecnt_t,bool) = &Playlist::copy;
 	return cut_copy (pmf, ranges, result_is_hidden);
 }
 
 boost::shared_ptr<Playlist>
-Playlist::cut (nframes_t start, nframes_t cnt, bool result_is_hidden)
+Playlist::cut (framepos_t start, framecnt_t cnt, bool result_is_hidden)
 {
 	boost::shared_ptr<Playlist> the_copy;
 	RegionList thawlist;
@@ -1034,7 +1088,7 @@ Playlist::cut (nframes_t start, nframes_t cnt, bool result_is_hidden)
 }
 
 boost::shared_ptr<Playlist>
-Playlist::copy (nframes_t start, nframes_t cnt, bool result_is_hidden)
+Playlist::copy (framepos_t start, framecnt_t cnt, bool result_is_hidden)
 {
 	char buf[32];
 
@@ -1048,10 +1102,10 @@ Playlist::copy (nframes_t start, nframes_t cnt, bool result_is_hidden)
 }
 
 int
-Playlist::paste (boost::shared_ptr<Playlist> other, nframes_t position, float times)
+Playlist::paste (boost::shared_ptr<Playlist> other, framepos_t position, float times)
 {
 	times = fabs (times);
-	nframes_t old_length;
+	framecnt_t old_length;
 
 	{
 		RegionLock rl1 (this);
@@ -1060,8 +1114,8 @@ Playlist::paste (boost::shared_ptr<Playlist> other, nframes_t position, float ti
 		old_length = _get_maximum_extent();
 
 		int itimes = (int) floor (times);
-		nframes_t pos = position;
-		nframes_t shift = other->_get_maximum_extent();
+		framepos_t pos = position;
+		framecnt_t shift = other->_get_maximum_extent();
 		layer_t top_layer = regions.size();
 
 		while (itimes--) {
@@ -1093,13 +1147,13 @@ Playlist::paste (boost::shared_ptr<Playlist> other, nframes_t position, float ti
 
 
 void
-Playlist::duplicate (boost::shared_ptr<Region> region, nframes_t position, float times)
+Playlist::duplicate (boost::shared_ptr<Region> region, framepos_t position, float times)
 {
 	times = fabs (times);
 
 	RegionLock rl (this);
 	int itimes = (int) floor (times);
-	nframes_t pos = position;
+	framepos_t pos = position;
 
 	while (itimes--) {
 		boost::shared_ptr<Region> copy = RegionFactory::create (region);
@@ -1108,16 +1162,25 @@ Playlist::duplicate (boost::shared_ptr<Region> region, nframes_t position, float
 	}
 
 	if (floor (times) != times) {
-		nframes_t length = (nframes_t) floor (region->length() * (times - floor (times)));
+		framecnt_t length = (framecnt_t) floor (region->length() * (times - floor (times)));
 		string name;
 		_session.region_name (name, region->name(), false);
-		boost::shared_ptr<Region> sub = RegionFactory::create (region, 0, length, name, region->layer(), region->flags());
-		add_region_internal (sub, pos);
+		
+		{
+			PropertyList plist;
+			
+			plist.add (Properties::start, 0);
+			plist.add (Properties::length, length);
+			plist.add (Properties::name, name);
+			
+			boost::shared_ptr<Region> sub = RegionFactory::create (region, plist);
+			add_region_internal (sub, pos);
+		}
 	}
 }
 
 void
-Playlist::shift (nframes64_t at, nframes64_t distance, bool move_intersected, bool ignore_music_glue)
+Playlist::shift (framepos_t at, frameoffset_t distance, bool move_intersected, bool ignore_music_glue)
 {
 	RegionLock rlock (this);
 	RegionList copy (regions);
@@ -1155,7 +1218,7 @@ Playlist::shift (nframes64_t at, nframes64_t distance, bool move_intersected, bo
 }
 
 void
-Playlist::split (nframes64_t at)
+Playlist::split (framepos_t at)
 {
 	RegionLock rlock (this);
 	RegionList copy (regions);
@@ -1169,14 +1232,14 @@ Playlist::split (nframes64_t at)
 }
 
 void
-Playlist::split_region (boost::shared_ptr<Region> region, nframes_t playlist_position)
+Playlist::split_region (boost::shared_ptr<Region> region, framepos_t playlist_position)
 {
 	RegionLock rl (this);
 	_split_region (region, playlist_position);
 }
 
 void
-Playlist::_split_region (boost::shared_ptr<Region> region, nframes_t playlist_position)
+Playlist::_split_region (boost::shared_ptr<Region> region, framepos_t playlist_position)
 {
 	if (!region->covers (playlist_position)) {
 		return;
@@ -1189,8 +1252,8 @@ Playlist::_split_region (boost::shared_ptr<Region> region, nframes_t playlist_po
 
 	boost::shared_ptr<Region> left;
 	boost::shared_ptr<Region> right;
-	nframes_t before;
-	nframes_t after;
+	frameoffset_t before;
+	frameoffset_t after;
 	string before_name;
 	string after_name;
 
@@ -1203,10 +1266,30 @@ Playlist::_split_region (boost::shared_ptr<Region> region, nframes_t playlist_po
 	after = region->length() - before;
 
 	_session.region_name (before_name, region->name(), false);
-	left = RegionFactory::create (region, 0, before, before_name, region->layer(), Region::Flag (region->flags()|Region::LeftOfSplit));
+
+	{
+		PropertyList plist;
+		
+		plist.add (Properties::start, 0);
+		plist.add (Properties::length, before);
+		plist.add (Properties::name, before_name);
+		plist.add (Properties::left_of_split, true);
+		
+		left = RegionFactory::create (region, plist);
+	}
 
 	_session.region_name (after_name, region->name(), false);
-	right = RegionFactory::create (region, before, after, after_name, region->layer(), Region::Flag (region->flags()|Region::RightOfSplit));
+
+	{
+		PropertyList plist;
+		
+		plist.add (Properties::start, before);
+		plist.add (Properties::length, after);
+		plist.add (Properties::name, after_name);
+		plist.add (Properties::right_of_split, true);
+
+		right = RegionFactory::create (region, plist);
+	}
 
 	add_region_internal (left, region->position());
 	add_region_internal (right, region->position() + before);
@@ -1231,7 +1314,7 @@ Playlist::_split_region (boost::shared_ptr<Region> region, nframes_t playlist_po
 }
 
 void
-Playlist::possibly_splice (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude)
+Playlist::possibly_splice (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude)
 {
 	if (_splicing || in_set_state) {
 		/* don't respond to splicing moves or state setting */
@@ -1244,7 +1327,7 @@ Playlist::possibly_splice (nframes_t at, nframes64_t distance, boost::shared_ptr
 }
 
 void
-Playlist::possibly_splice_unlocked (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude)
+Playlist::possibly_splice_unlocked (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude)
 {
 	if (_splicing || in_set_state) {
 		/* don't respond to splicing moves or state setting */
@@ -1257,7 +1340,7 @@ Playlist::possibly_splice_unlocked (nframes_t at, nframes64_t distance, boost::s
 }
 
 void
-Playlist::splice_locked (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude)
+Playlist::splice_locked (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude)
 {
 	{
 		RegionLock rl (this);
@@ -1266,13 +1349,13 @@ Playlist::splice_locked (nframes_t at, nframes64_t distance, boost::shared_ptr<R
 }
 
 void
-Playlist::splice_unlocked (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude)
+Playlist::splice_unlocked (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude)
 {
 	core_splice (at, distance, exclude);
 }
 
 void
-Playlist::core_splice (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude)
+Playlist::core_splice (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude)
 {
 	_splicing = true;
 
@@ -1283,7 +1366,7 @@ Playlist::core_splice (nframes_t at, nframes64_t distance, boost::shared_ptr<Reg
 		}
 
 		if ((*i)->position() >= at) {
-			nframes64_t new_pos = (*i)->position() + distance;
+			framepos_t new_pos = (*i)->position() + distance;
 			if (new_pos < 0) {
 				new_pos = 0;
 			} else if (new_pos >= max_frames - (*i)->length()) {
@@ -1300,7 +1383,7 @@ Playlist::core_splice (nframes_t at, nframes64_t distance, boost::shared_ptr<Reg
 }
 
 void
-Playlist::region_bounds_changed (Change what_changed, boost::shared_ptr<Region> region)
+Playlist::region_bounds_changed (PropertyChange what_changed, boost::shared_ptr<Region> region)
 {
 	if (in_set_state || _splicing || _nudging || _shuffling) {
 		return;
@@ -1327,16 +1410,16 @@ Playlist::region_bounds_changed (Change what_changed, boost::shared_ptr<Region>
 		regions.insert (upper_bound (regions.begin(), regions.end(), region, cmp), region);
 	}
 
-	if (what_changed & Change (ARDOUR::PositionChanged|ARDOUR::LengthChanged)) {
+	if (what_changed & PropertyChange (ARDOUR::PositionChanged|ARDOUR::LengthChanged)) {
 
-		nframes64_t delta = 0;
+		frameoffset_t delta = 0;
 
 		if (what_changed & ARDOUR::PositionChanged) {
-			delta = (nframes64_t) region->position() - (nframes64_t) region->last_position();
+			delta = region->position() - region->last_position();
 		}
 
 		if (what_changed & ARDOUR::LengthChanged) {
-			delta += (nframes64_t) region->length() - (nframes64_t) region->last_length();
+			delta += region->length() - region->last_length();
 		}
 
 		if (delta) {
@@ -1359,7 +1442,7 @@ Playlist::region_bounds_changed (Change what_changed, boost::shared_ptr<Region>
 }
 
 void
-Playlist::region_changed_proxy (Change what_changed, boost::weak_ptr<Region> weak_region)
+Playlist::region_changed_proxy (PropertyChange what_changed, boost::weak_ptr<Region> weak_region)
 {
 	boost::shared_ptr<Region> region (weak_region.lock());
 
@@ -1373,9 +1456,9 @@ Playlist::region_changed_proxy (Change what_changed, boost::weak_ptr<Region> wea
 }
 
 bool
-Playlist::region_changed (Change what_changed, boost::shared_ptr<Region> region)
+Playlist::region_changed (PropertyChange what_changed, boost::shared_ptr<Region> region)
 {
-	Change our_interests = Change (Region::MuteChanged|Region::LayerChanged|Region::OpacityChanged);
+	PropertyChange our_interests = PropertyChange (Region::MuteChanged|Region::LayerChanged|Region::OpacityChanged);
 	bool save = false;
 
 	if (in_set_state || in_flush) {
@@ -1388,11 +1471,11 @@ Playlist::region_changed (Change what_changed, boost::shared_ptr<Region> region)
 	}
 
 	if ((what_changed & our_interests) &&
-	    !(what_changed & Change (ARDOUR::PositionChanged|ARDOUR::LengthChanged))) {
+	    !(what_changed & PropertyChange (ARDOUR::PositionChanged|ARDOUR::LengthChanged))) {
 		check_dependents (region, false);
 	}
 
-	if (what_changed & Change (ARDOUR::PositionChanged)) {
+	if (what_changed & PropertyChange (ARDOUR::PositionChanged)) {
 		notify_region_moved (region);
 	}
 
@@ -1447,7 +1530,7 @@ Playlist::clear (bool with_signals)
  **********************************************************************/
 
 Playlist::RegionList *
-Playlist::regions_at (nframes_t frame)
+Playlist::regions_at (framepos_t frame)
 
 {
 	RegionLock rlock (this);
@@ -1455,7 +1538,7 @@ Playlist::regions_at (nframes_t frame)
 }
 
 boost::shared_ptr<Region>
-Playlist::top_region_at (nframes_t frame)
+Playlist::top_region_at (framepos_t frame)
 
 {
 	RegionLock rlock (this);
@@ -1473,7 +1556,7 @@ Playlist::top_region_at (nframes_t frame)
 }
 
 boost::shared_ptr<Region>
-Playlist::top_unmuted_region_at (nframes_t frame)
+Playlist::top_unmuted_region_at (framepos_t frame)
 
 {
 	RegionLock rlock (this);
@@ -1504,12 +1587,12 @@ Playlist::top_unmuted_region_at (nframes_t frame)
 }
 
 Playlist::RegionList*
-Playlist::regions_to_read (nframes_t start, nframes_t end)
+Playlist::regions_to_read (framepos_t start, framepos_t end)
 {
 	/* Caller must hold lock */
 
 	RegionList covering;
-	set<nframes_t> to_check;
+	set<framepos_t> to_check;
 	set<boost::shared_ptr<Region> > unique;
 	RegionList here;
 
@@ -1562,7 +1645,7 @@ Playlist::regions_to_read (nframes_t start, nframes_t end)
 
 	} else {
 
-		for (set<nframes_t>::iterator t = to_check.begin(); t != to_check.end(); ++t) {
+		for (set<framepos_t>::iterator t = to_check.begin(); t != to_check.end(); ++t) {
 
 			here.clear ();
 
@@ -1607,7 +1690,7 @@ Playlist::regions_to_read (nframes_t start, nframes_t end)
 }
 
 Playlist::RegionList *
-Playlist::find_regions_at (nframes_t frame)
+Playlist::find_regions_at (framepos_t frame)
 {
 	/* Caller must hold lock */
 
@@ -1623,7 +1706,7 @@ Playlist::find_regions_at (nframes_t frame)
 }
 
 Playlist::RegionList *
-Playlist::regions_touched (nframes_t start, nframes_t end)
+Playlist::regions_touched (framepos_t start, framepos_t end)
 {
 	RegionLock rlock (this);
 	RegionList *rlist = new RegionList;
@@ -1637,8 +1720,8 @@ Playlist::regions_touched (nframes_t start, nframes_t end)
 	return rlist;
 }
 
-nframes64_t
-Playlist::find_next_transient (nframes64_t from, int dir)
+framepos_t
+Playlist::find_next_transient (framepos_t from, int dir)
 {
 	RegionLock rlock (this);
 	AnalysisFeatureList points;
@@ -1698,11 +1781,11 @@ Playlist::find_next_transient (nframes64_t from, int dir)
 }
 
 boost::shared_ptr<Region>
-Playlist::find_next_region (nframes_t frame, RegionPoint point, int dir)
+Playlist::find_next_region (framepos_t frame, RegionPoint point, int dir)
 {
 	RegionLock rlock (this);
 	boost::shared_ptr<Region> ret;
-	nframes_t closest = max_frames;
+	framepos_t closest = max_frames;
 
 	bool end_iter = false;
 
@@ -1710,9 +1793,9 @@ Playlist::find_next_region (nframes_t frame, RegionPoint point, int dir)
 
 		if(end_iter) break;
 
-		nframes_t distance;
+		frameoffset_t distance;
 		boost::shared_ptr<Region> r = (*i);
-		nframes_t pos = 0;
+		framepos_t pos = 0;
 
 		switch (point) {
 		case Start:
@@ -1759,20 +1842,20 @@ Playlist::find_next_region (nframes_t frame, RegionPoint point, int dir)
 	return ret;
 }
 
-nframes64_t
-Playlist::find_next_region_boundary (nframes64_t frame, int dir)
+framepos_t
+Playlist::find_next_region_boundary (framepos_t frame, int dir)
 {
 	RegionLock rlock (this);
 
-	nframes64_t closest = max_frames;
-	nframes64_t ret = -1;
+	framepos_t closest = max_frames;
+	framepos_t ret = -1;
 
 	if (dir > 0) {
 
 		for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
 
 			boost::shared_ptr<Region> r = (*i);
-			nframes64_t distance;
+			frameoffset_t distance;
 
 			if (r->first_frame() > frame) {
 
@@ -1800,7 +1883,7 @@ Playlist::find_next_region_boundary (nframes64_t frame, int dir)
 		for (RegionList::reverse_iterator i = regions.rbegin(); i != regions.rend(); ++i) {
 
 			boost::shared_ptr<Region> r = (*i);
-			nframes64_t distance;
+			frameoffset_t distance;
 
 			if (r->last_frame() < frame) {
 
@@ -1895,15 +1978,13 @@ Playlist::set_state (const XMLNode& node, int version)
 
 			if ((region = region_by_id (id))) {
 
-				Change what_changed = Change (0);
-
 				region->freeze ();
 
-				if (region->set_live_state (*child, version, what_changed, false)) {
+				if (region->set_state (*child, version)) {
 					region->thaw ();
 					continue;
 				}
-
+				
 			} else if ((region = RegionFactory::create (_session, *child, true)) != 0) {
 				region->freeze ();
 			} else {
@@ -1991,19 +2072,19 @@ Playlist::n_regions() const
 	return regions.size();
 }
 
-nframes_t
+framecnt_t
 Playlist::get_maximum_extent () const
 {
 	RegionLock rlock (const_cast<Playlist *>(this), false);
 	return _get_maximum_extent ();
 }
 
-ARDOUR::nframes_t
+framecnt_t
 Playlist::_get_maximum_extent () const
 {
 	RegionList::const_iterator i;
-	nframes_t max_extent = 0;
-	nframes_t end = 0;
+	framecnt_t max_extent = 0;
+	framepos_t end = 0;
 
 	for (i = regions.begin(); i != regions.end(); ++i) {
 		if ((end = (*i)->position() + (*i)->length()) > max_extent) {
@@ -2063,8 +2144,8 @@ Playlist::relayer ()
 	int const divisions = 512;
 
 	/* find the start and end positions of the regions on this playlist */
-	nframes_t start = UINT_MAX;
-	nframes_t end = 0;
+	framepos_t start = UINT_MAX;
+	framepos_t end = 0;
 	for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
 		start = min (start, (*i)->position());
 		end = max (end, (*i)->position() + (*i)->length());
@@ -2286,10 +2367,10 @@ Playlist::move_region_to_layer (layer_t target_layer, boost::shared_ptr<Region>
 }
 
 void
-Playlist::nudge_after (nframes_t start, nframes_t distance, bool forwards)
+Playlist::nudge_after (framepos_t start, framecnt_t distance, bool forwards)
 {
 	RegionList::iterator i;
-	nframes_t new_pos;
+	framepos_t new_pos;
 	bool moved = false;
 
 	_nudging = true;
@@ -2400,7 +2481,7 @@ void
 Playlist::shuffle (boost::shared_ptr<Region> region, int dir)
 {
 	bool moved = false;
-	nframes_t new_pos;
+	framepos_t new_pos;
 
 	if (region->locked()) {
 		return;
@@ -2570,7 +2651,7 @@ Playlist::set_explicit_relayering (bool e)
 
 
 bool
-Playlist::has_region_at (nframes64_t const p) const
+Playlist::has_region_at (framepos_t const p) const
 {
 	RegionLock (const_cast<Playlist *> (this));
 	
diff --git a/libs/ardour/region.cc b/libs/ardour/region.cc
index 21721a484a..740a4abd5e 100644
--- a/libs/ardour/region.cc
+++ b/libs/ardour/region.cc
@@ -46,161 +46,318 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
-Change Region::FadeChanged       = PBD::new_change ();
-Change Region::SyncOffsetChanged = PBD::new_change ();
-Change Region::MuteChanged       = PBD::new_change ();
-Change Region::OpacityChanged    = PBD::new_change ();
-Change Region::LockChanged       = PBD::new_change ();
-Change Region::LayerChanged      = PBD::new_change ();
-Change Region::HiddenChanged     = PBD::new_change ();
-
+PropertyChange Region::FadeChanged       = PBD::new_change ();
+PropertyChange Region::SyncOffsetChanged = PBD::new_change ();
+PropertyChange Region::MuteChanged       = PBD::new_change ();
+PropertyChange Region::OpacityChanged    = PBD::new_change ();
+PropertyChange Region::LockChanged       = PBD::new_change ();
+PropertyChange Region::LayerChanged      = PBD::new_change ();
+PropertyChange Region::HiddenChanged     = PBD::new_change ();
+
+namespace ARDOUR { 
+	namespace Properties {
+		PBD::PropertyDescriptor<bool> muted;
+		PBD::PropertyDescriptor<bool> opaque;
+		PBD::PropertyDescriptor<bool> locked;
+		PBD::PropertyDescriptor<bool> automatic;
+		PBD::PropertyDescriptor<bool> whole_file;
+		PBD::PropertyDescriptor<bool> import;
+		PBD::PropertyDescriptor<bool> external;
+		PBD::PropertyDescriptor<bool> sync_marked;
+		PBD::PropertyDescriptor<bool> left_of_split;
+		PBD::PropertyDescriptor<bool> right_of_split;
+		PBD::PropertyDescriptor<bool> hidden;
+		PBD::PropertyDescriptor<bool> position_locked;
+		PBD::PropertyDescriptor<framepos_t> start;
+		PBD::PropertyDescriptor<framecnt_t> length;
+		PBD::PropertyDescriptor<framepos_t> position;
+		PBD::PropertyDescriptor<framecnt_t> sync_position;
+		PBD::PropertyDescriptor<layer_t> layer;
+		PBD::PropertyDescriptor<framepos_t> ancestral_start;
+		PBD::PropertyDescriptor<framecnt_t> ancestral_length;
+		PBD::PropertyDescriptor<float> stretch;
+		PBD::PropertyDescriptor<float> shift;
+	}
+}
+	
 PBD::Signal1<void,boost::shared_ptr<ARDOUR::Region> > Region::RegionPropertyChanged;
 
 void
-Region::register_states ()
+Region::make_property_quarks ()
+{
+	Properties::muted.id = g_quark_from_static_string (X_("muted"));
+	Properties::opaque.id = g_quark_from_static_string (X_("opaque"));
+	Properties::locked.id = g_quark_from_static_string (X_("locked"));
+	Properties::automatic.id = g_quark_from_static_string (X_("automatic"));
+	Properties::whole_file.id = g_quark_from_static_string (X_("whole-file"));
+	Properties::import.id = g_quark_from_static_string (X_("import"));
+	Properties::external.id = g_quark_from_static_string (X_("external"));
+	Properties::sync_marked.id = g_quark_from_static_string (X_("sync-marked"));
+	Properties::left_of_split.id = g_quark_from_static_string (X_("left-of-split"));
+	Properties::right_of_split.id = g_quark_from_static_string (X_("right-of-split"));
+	Properties::hidden.id = g_quark_from_static_string (X_("hidden"));
+	Properties::position_locked.id = g_quark_from_static_string (X_("position-locked"));
+	Properties::start.id = g_quark_from_static_string (X_("start"));
+	Properties::length.id = g_quark_from_static_string (X_("length"));
+	Properties::position.id = g_quark_from_static_string (X_("position"));
+	Properties::sync_position.id = g_quark_from_static_string (X_("sync-position"));
+	Properties::layer.id = g_quark_from_static_string (X_("layer"));
+	Properties::ancestral_start.id = g_quark_from_static_string (X_("ancestral-start"));
+	Properties::ancestral_length.id = g_quark_from_static_string (X_("ancestral-length"));
+	Properties::stretch.id = g_quark_from_static_string (X_("stretch"));
+	Properties::shift.id = g_quark_from_static_string (X_("shift"));
+}
+
+void
+Region::register_properties ()
 {
 	_xml_node_name = X_("Region");
-	add_state (_flags);
-	add_state (_start);
-	add_state (_length);
-	add_state (_position);
-	add_state (_sync_position);
-	add_state (_layer);
-	add_state (_ancestral_start);
-	add_state (_ancestral_length);
-	add_state (_stretch);
-	add_state (_shift);
-}
+
+	add_property (_muted);
+	add_property (_opaque);
+	add_property (_locked);
+	add_property (_automatic);
+	add_property (_whole_file);
+	add_property (_import);
+	add_property (_external);
+	add_property (_sync_marked);
+	add_property (_left_of_split);
+	add_property (_right_of_split);
+	add_property (_hidden);
+	add_property (_position_locked);
+	add_property (_start);
+	add_property (_length);
+	add_property (_position);
+	add_property (_sync_position);
+	add_property (_layer);
+	add_property (_ancestral_start);
+	add_property (_ancestral_length);
+	add_property (_stretch);
+	add_property (_shift);
+}
+
+#define REGION_DEFAULT_STATE(s,l) \
+	_muted (Properties::muted, MuteChanged, false)	     \
+	, _opaque (Properties::opaque, OpacityChanged, true) \
+	, _locked (Properties::locked, LockChanged, false) \
+	, _automatic (Properties::automatic, PropertyChange (0), false) \
+	, _whole_file (Properties::whole_file, PropertyChange (0), false) \
+	, _import (Properties::import, PropertyChange (0), false) \
+	, _external (Properties::external, PropertyChange (0), false) \
+	, _sync_marked (Properties::sync_marked, SyncOffsetChanged, false) \
+	, _left_of_split (Properties::left_of_split, PropertyChange (0), false) \
+	, _right_of_split (Properties::right_of_split, PropertyChange (0), false) \
+	, _hidden (Properties::hidden, HiddenChanged, false) \
+	, _position_locked (Properties::position_locked, PropertyChange (0), false) \
+	, _start (Properties::start, StartChanged, (s))	\
+	, _length (Properties::length, LengthChanged, (l))	\
+	, _position (Properties::position, PositionChanged, 0) \
+	, _sync_position (Properties::sync_position, SyncOffsetChanged, (s)) \
+	, _layer (Properties::layer, LayerChanged, 0)	\
+	, _ancestral_start (Properties::ancestral_start, PropertyChange (0), (s)) \
+	, _ancestral_length (Properties::ancestral_length, PropertyChange (0), (l)) \
+	, _stretch (Properties::stretch, PropertyChange (0), 1.0) \
+	, _shift (Properties::shift, PropertyChange (0), 1.0)
+
+#define REGION_COPY_STATE(other) \
+	  _muted (other->_muted) \
+	, _opaque (other->_opaque) \
+	, _locked (other->_locked) \
+	, _automatic (other->_automatic) \
+	, _whole_file (other->_whole_file) \
+	, _import (other->_import) \
+	, _external (other->_external) \
+	, _sync_marked (other->_sync_marked) \
+	, _left_of_split (other->_left_of_split) \
+	, _right_of_split (other->_right_of_split) \
+	, _hidden (other->_hidden) \
+	, _position_locked (other->_position_locked) \
+	, _start(other->_start) \
+	, _length(other->_length) \
+	, _position(other->_position) \
+	, _sync_position(other->_sync_position) \
+        , _layer (other->_layer) \
+	, _ancestral_start (other->_ancestral_start) \
+	, _ancestral_length (other->_ancestral_length) \
+	, _stretch (other->_stretch) \
+	, _shift (other->_shift)
 
 /* derived-from-derived constructor (no sources in constructor) */
-Region::Region (Session& s, nframes_t start, nframes_t length, const string& name, DataType type, layer_t layer, Region::Flag flags)
+Region::Region (Session& s, framepos_t start, framecnt_t length, const string& name, DataType type)
 	: SessionObject(s, name)
 	, _type(type)
-	, _flags (X_("flags"), FlagsChanged, Flag (flags|DoNotSendPropertyChanges))
-	, _start (X_("start"), StartChanged, start)
-	, _length (X_("length"), LengthChanged, length)
-	, _position (X_("position"), PositionChanged, 0)
+	, _no_property_changes (true)
+	, REGION_DEFAULT_STATE(start,length)
+	, _last_length (length)
 	, _last_position (0)
 	, _positional_lock_style(AudioTime)
-	, _sync_position (X_("sync-position"), SyncOffsetChanged, _start)
-	, _layer (X_("layer"), LayerChanged, layer)
-	, _first_edit(EditChangesNothing)
+	, _first_edit (EditChangesNothing)
 	, _frozen(0)
-	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
-	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
-	, _stretch (X_("stretch"), Change (0), 1.0)
-	, _shift (X_("shift"), Change (0), 1.0)
 	, _read_data_count(0)
-	, _pending_changed(Change (0))
+	, _pending_changed(PropertyChange (0))
 	, _last_layer_op(0)
 	, _pending_explicit_relayer (false)
 {
-	register_states ();
-	
+	register_properties ();
+
 	/* no sources at this point */
 }
 
 /** Basic Region constructor (single source) */
-Region::Region (boost::shared_ptr<Source> src, nframes_t start, nframes_t length, const string& name, DataType type, layer_t layer, Region::Flag flags)
-	: SessionObject(src->session(), name)
-	, _type(type)
-	, _flags (X_("flags"), FlagsChanged, Flag (flags|DoNotSendPropertyChanges))
-	, _start (X_("start"), StartChanged, start)
-	, _length (X_("length"), LengthChanged, length)
-	, _position (X_("position"), PositionChanged, 0)
-	, _last_position(0)
-	, _positional_lock_style(AudioTime)
-	, _sync_position (X_("sync-position"), SyncOffsetChanged, _start)
-	, _layer (X_("layer"), LayerChanged, layer)
-	, _first_edit(EditChangesNothing)
+Region::Region (boost::shared_ptr<Source> src)
+	: SessionObject(src->session(), "toBeRenamed")
+	, _type (src->type())
+	, _no_property_changes (true)
+	, REGION_DEFAULT_STATE(0,0)
+	, _last_length (0)
+	, _last_position (0)
+        , _positional_lock_style (_type == DataType::AUDIO ? AudioTime : MusicTime)
+	, _first_edit (EditChangesNothing)
 	, _frozen(0)
-	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
-	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
-	, _stretch (X_("stretch"), Change (0), 1.0)
-	, _shift (X_("shift"), Change (0), 1.0)
 	, _valid_transients(false)
 	, _read_data_count(0)
-	, _pending_changed(Change (0))
+	, _pending_changed(PropertyChange (0))
 	, _last_layer_op(0)
 	, _pending_explicit_relayer (false)
 {
-	register_states ();
+	register_properties ();
 
 	_sources.push_back (src);
 	_master_sources.push_back (src);
 
 	src->DropReferences.connect_same_thread (*this, boost::bind (&Region::source_deleted, this, boost::weak_ptr<Source>(src)));
-
-	assert(_sources.size() > 0);
-	_positional_lock_style = AudioTime;
+	
+	assert (_sources.size() > 0);
+	assert (_type == src->type());
 }
 
 /** Basic Region constructor (many sources) */
-Region::Region (const SourceList& srcs, nframes_t start, nframes_t length, const string& name, DataType type, layer_t layer, Region::Flag flags)
-	: SessionObject(srcs.front()->session(), name)
-	, _type(type)
-	, _flags (X_("flags"), FlagsChanged, Flag (flags|DoNotSendPropertyChanges))
-	, _start (X_("start"), StartChanged, start)
-	, _length (X_("length"), LengthChanged, length)
-	, _position (X_("position"), PositionChanged, 0)
-	, _last_position(0)
-	, _positional_lock_style(AudioTime)
-	, _sync_position (X_("sync-position"), SyncOffsetChanged, _start)
-	, _layer (X_("layer"), LayerChanged, layer)
-	, _first_edit(EditChangesNothing)
-	, _frozen(0)
-	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
-	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
-	, _stretch (X_("stretch"), Change (0), 1.0)
-	, _shift (X_("shift"), Change (0), 1.0)
+Region::Region (const SourceList& srcs)
+	: SessionObject(srcs.front()->session(), "toBeRenamed")
+	, _type (srcs.front()->type())
+	, _no_property_changes (true)
+	, REGION_DEFAULT_STATE(0,0)
+	, _last_length (0)
+	, _last_position (0)
+        , _positional_lock_style (_type == DataType::AUDIO ? AudioTime : MusicTime)
+	, _first_edit (EditChangesNothing)
+	, _frozen (0)
+	, _valid_transients(false)
 	, _read_data_count(0)
-	, _pending_changed(Change (0))
-	, _last_layer_op(0)
+	, _pending_changed(PropertyChange (0))
+	, _last_layer_op (0)
 	, _pending_explicit_relayer (false)
 {
-	register_states ();
+	register_properties ();
+
+	_type = srcs.front()->type();
 
 	use_sources (srcs);
+
 	assert(_sources.size() > 0);
+	assert (_type == srcs.front()->type());
 }
 
-/** Create a new Region from part of an existing one */
-Region::Region (boost::shared_ptr<const Region> other, nframes_t offset, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: SessionObject(other->session(), name)
+/** Create a new Region from part of an existing one, starting at one of two places:
+
+    if @param offset_relative is true, then the start within @param other is given by @param offset
+    (i.e. relative to the start of @param other's sources, the start is @param offset + @param other.start()
+
+    if @param offset_relative is false, then the start within the source is given @param offset.
+*/
+Region::Region (boost::shared_ptr<const Region> other, frameoffset_t offset, bool offset_relative)
+	: SessionObject(other->session(), "toBeRenamed")
 	, _type (other->data_type())
-	, _flags (X_("flags"), FlagsChanged, Flag (flags | DoNotSendPropertyChanges))
-	, _start (X_("start"), StartChanged, 0)
-	, _length (X_("length"), LengthChanged, 0)
-	, _position (X_("position"), PositionChanged, 0)
-	, _sync_position (X_("sync-position"), SyncOffsetChanged, 0)
-	, _layer (X_("layer"), LayerChanged, 0)
-	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
-	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
-	, _stretch (X_("stretch"), Change (0), 1.0)
-	, _shift (X_("shift"), Change (0), 1.0)
+	, _no_property_changes (true)
+	, REGION_COPY_STATE (other)
+	, _last_length (other->_last_length)
+	, _last_position(other->_last_position) \
+	, _positional_lock_style(other->_positional_lock_style) \
+	, _first_edit (EditChangesNothing)
+	, _frozen (0)
+	, _valid_transients(false)
+	, _read_data_count(0)
+	, _pending_changed(PropertyChange (0))
+	, _last_layer_op (0)
 	, _pending_explicit_relayer (false)
 
 {
-	register_states ();
+	register_properties ();
 
-	_start = other->_start + offset;
-	copy_stuff (other, offset, length, name, layer, flags);
+	/* override state that may have been incorrectly inherited from the other region
+	 */
 
-	/* if the other region had a distinct sync point
-	   set, then continue to use it as best we can.
-	   otherwise, reset sync point back to start.
-	*/
+	_position = 0;
+	_locked = false;
+	_whole_file = false;
+	_hidden = false;
 
-	if (other->flags() & SyncMarked) {
-		if (other->_sync_position < _start) {
-			_flags = Flag (_flags & ~SyncMarked);
-			_sync_position = _start;
+	use_sources (other->_sources);
+
+	if (!offset_relative) {
+
+		/* not sure why we do this, but its a hangover from ardour before
+		   property lists. this would be nice to remove.
+		*/
+
+		_positional_lock_style = other->_positional_lock_style;
+		_first_edit = other->_first_edit;
+
+		if (offset == 0) {
+
+			_start = 0;
+
+			/* sync pos is relative to start of file. our start-in-file is now zero,
+			   so set our sync position to whatever the the difference between
+			   _start and _sync_pos was in the other region.
+			   
+			   result is that our new sync pos points to the same point in our source(s)
+			   as the sync in the other region did in its source(s).
+			   
+			   since we start at zero in our source(s), it is not possible to use a sync point that
+			   is before the start. reset it to _start if that was true in the other region.
+			*/
+			
+			if (other->sync_marked()) {
+				if (other->_start < other->_sync_position) {
+					/* sync pos was after the start point of the other region */
+					_sync_position = other->_sync_position - other->_start;
+				} else {
+					/* sync pos was before the start point of the other region. not possible here. */
+					_sync_marked = false;
+					_sync_position = _start;
+				}
+			} else {
+				_sync_marked = false;
+				_sync_position = _start;
+			}
 		} else {
-			_sync_position = other->_sync_position;
+			/* XXX do something else ! */
+			fatal << string_compose (_("programming error: %1"), X_("Region+offset constructor used with illegal combination of offset+relative"))
+			      << endmsg;
+			/*NOTREACHED*/
 		}
+
 	} else {
-		_flags = Flag (_flags & ~SyncMarked);
-		_sync_position = _start;
+
+		_start = other->_start + offset;
+		
+		/* if the other region had a distinct sync point
+		   set, then continue to use it as best we can.
+		   otherwise, reset sync point back to start.
+		*/
+		
+		if (other->sync_marked()) {
+			if (other->_sync_position < _start) {
+				_sync_marked = false;
+				_sync_position = _start;
+		} else {
+				_sync_position = other->_sync_position;
+			}
+		} else {
+			_sync_marked = false;
+			_sync_position = _start;
+		}
 	}
 
 	if (Profile->get_sae()) {
@@ -209,106 +366,69 @@ Region::Region (boost::shared_ptr<const Region> other, nframes_t offset, nframes
 		*/
 
 		if (_sync_position < _start || _sync_position >= _start + _length) {
-			_flags = Flag (_flags & ~SyncMarked);
+			_sync_marked = false;
 			_sync_position = _start;
 		}
 	}
-}
 
-Region::Region (boost::shared_ptr<const Region> other, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: SessionObject(other->session(), name)
-	, _type (other->data_type())
-	, _flags (X_("flags"), FlagsChanged, Flag (flags|DoNotSendPropertyChanges))
-	, _start (X_("start"), StartChanged, 0)
-	, _length (X_("length"), LengthChanged, 0)
-	, _position (X_("position"), PositionChanged, 0)
-	, _sync_position (X_("sync-position"), SyncOffsetChanged, 0)
-	, _layer (X_("layer"), LayerChanged, 0)
-	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
-	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
-	, _stretch (X_("stretch"), Change (0), 1.0)
-	, _shift (X_("shift"), Change (0), 1.0)
+	assert (_type == other->data_type());
+}
+
+/** Create a copy of @param other but with different sources. Used by filters */
+Region::Region (boost::shared_ptr<const Region> other, const SourceList& srcs)
+	: SessionObject (other->session(), other->name())
+	, _type (srcs.front()->type())
+	, _no_property_changes (true)
+	, REGION_COPY_STATE (other)
+	, _last_length (other->_last_length)
+	, _last_position (other->_last_position)
+        , _positional_lock_style (other->_positional_lock_style)
+	, _first_edit (EditChangesID)
+	, _frozen (0)
+	, _valid_transients (false)
+	, _read_data_count (0)
+	, _pending_changed (PropertyChange(0))
+	, _last_layer_op (other->_last_layer_op)
 	, _pending_explicit_relayer (false)
 {
-	register_states ();
-
-	/* create a new Region exactly like another but starting at 0 in its sources */
+	register_properties ();
 
-	_start = 0;
-	copy_stuff (other, 0, length, name, layer, flags);
+	_locked = false;
+	_position_locked = false;
 
-	_flags = Flag (_flags | DoNotSendPropertyChanges);
-
-	/* sync pos is relative to start of file. our start-in-file is now zero,
-	   so set our sync position to whatever the the difference between
-	   _start and _sync_pos was in the other region.
-
-	   result is that our new sync pos points to the same point in our source(s)
-	   as the sync in the other region did in its source(s).
-
-	   since we start at zero in our source(s), it is not possible to use a sync point that
-	   is before the start. reset it to _start if that was true in the other region.
-	*/
+	other->_first_edit = EditChangesName;
 
-	if (other->flags() & SyncMarked) {
-		if (other->_start < other->_sync_position) {
-			/* sync pos was after the start point of the other region */
-			_sync_position = other->_sync_position - other->_start;
-		} else {
-			/* sync pos was before the start point of the other region. not possible here. */
-			_flags = Flag (_flags & ~SyncMarked);
-			_sync_position = _start;
-		}
+	if (other->_extra_xml) {
+		_extra_xml = new XMLNode (*other->_extra_xml);
 	} else {
-		_flags = Flag (_flags & ~SyncMarked);
-		_sync_position = _start;
-	}
-
-	if (Profile->get_sae()) {
-		/* reset sync point to start if its ended up
-		   outside region bounds.
-		*/
-
-		if (_sync_position < _start || _sync_position >= _start + _length) {
-			_flags = Flag (_flags & ~SyncMarked);
-			_sync_position = _start;
-		}
+		_extra_xml = 0;
 	}
 
-	/* reset a couple of things that copy_stuff() gets wrong in this particular case */
-
-	_positional_lock_style = other->_positional_lock_style;
-	_first_edit = other->_first_edit;
+	use_sources (srcs);
+	assert(_sources.size() > 0);
 }
 
-/** Pure copy constructor */
+/** Simple "copy" constructor */
 Region::Region (boost::shared_ptr<const Region> other)
 	: SessionObject(other->session(), other->name())
 	, _type(other->data_type())
-	, _flags (other->_flags)
-	, _start(other->_start)
-	, _length(other->_length)
-	, _position(other->_position)
-	, _last_position(other->_last_position)
-	, _positional_lock_style(other->_positional_lock_style)
-	, _sync_position(other->_sync_position)
-	, _layer(other->_layer)
-	, _first_edit(EditChangesID)
+	, _no_property_changes (true)
+	, REGION_COPY_STATE (other)
+	, _last_length (other->_last_length)
+	, _last_position (other->_last_position)
+        , _positional_lock_style (other->_positional_lock_style)
+	, _first_edit (EditChangesID)
 	, _frozen(0)
-	, _ancestral_start (other->_ancestral_start)
-	, _ancestral_length (other->_ancestral_length)
-	, _stretch (other->_stretch)
-	, _shift (other->_shift)
 	, _valid_transients(false)
 	, _read_data_count(0)
-	, _pending_changed(Change(0))
+	, _pending_changed(PropertyChange(0))
 	, _last_layer_op(other->_last_layer_op)
 	, _pending_explicit_relayer (false)
 {
-	register_states ();
+	register_properties ();
 
-	_flags = Flag (_flags & ~ (Locked | PositionLocked));
-	_flags = Flag (_flags | DoNotSendPropertyChanges);
+	_locked = false;
+	_position_locked = false;
 
 	other->_first_edit = EditChangesName;
 
@@ -324,27 +444,26 @@ Region::Region (boost::shared_ptr<const Region> other)
 
 Region::Region (const SourceList& srcs, const XMLNode& node)
 	: SessionObject(srcs.front()->session(), X_("error: XML did not reset this"))
-	, _type(DataType::NIL) // to be loaded from XML
-	, _flags (X_("flags"), FlagsChanged, Flag (DoNotSendPropertyChanges))
-	, _start (X_("start"), StartChanged, 0)
-	, _length (X_("length"), LengthChanged, 0)
-	, _position (X_("position"), PositionChanged, 0)
-	, _last_position(0)
-	, _positional_lock_style(AudioTime)
-	, _sync_position (X_("sync-position"), SyncOffsetChanged, _start)
-	, _layer (X_("layer"), LayerChanged, 0)
-	, _first_edit(EditChangesNothing)
+	, _type (srcs.front()->type())
+	, REGION_DEFAULT_STATE(0,0)
+	, _last_length (0)
+	, _last_position (0)
+        , _positional_lock_style (_type == DataType::AUDIO ? AudioTime : MusicTime)
+	, _first_edit (EditChangesNothing)
 	, _frozen(0)
-	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
-	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
-	, _stretch (X_("stretch"), Change (0), 1.0)
-	, _shift (X_("shift"), Change (0), 1.0)
+	, _valid_transients(false)
 	, _read_data_count(0)
-	, _pending_changed(Change(0))
+	, _pending_changed(PropertyChange(0))
 	, _last_layer_op(0)
 	, _pending_explicit_relayer (false)
 {
-	register_states ();
+	const XMLProperty* prop;
+
+	register_properties ();
+
+	if ((prop = node.property (X_("id")))) {
+		_id = prop->value();
+	}
 
 	use_sources (srcs);
 
@@ -354,40 +473,41 @@ Region::Region (const SourceList& srcs, const XMLNode& node)
 
 	assert(_type != DataType::NIL);
 	assert(_sources.size() > 0);
+	assert (_type == srcs.front()->type());
+
 }
 
 Region::Region (boost::shared_ptr<Source> src, const XMLNode& node)
 	: SessionObject(src->session(), X_("error: XML did not reset this"))
-	, _type(DataType::NIL)
-	, _flags (X_("flags"), FlagsChanged, Flag (DoNotSendPropertyChanges))
-	, _start (X_("start"), StartChanged, 0)
-	, _length (X_("length"), LengthChanged, 0)
-	, _position (X_("position"), PositionChanged, 0)
-	, _last_position(0)
-	, _positional_lock_style(AudioTime)
-	, _sync_position (X_("sync-position"), SyncOffsetChanged, _start)
-	, _layer (X_("layer"), LayerChanged, 0)
-	, _first_edit(EditChangesNothing)
-	, _frozen(0)
-	, _ancestral_start (X_("ancestral-start"), Change (0), 0)
-	, _ancestral_length (X_("ancestral-length"), Change (0), 0)
-	, _stretch (X_("stretch"), Change (0), 1.0)
-	, _shift (X_("shift"), Change (0), 1.0)
-	, _read_data_count(0)
-	, _pending_changed(Change(0))
-	, _last_layer_op(0)
+	, _type (src->type())
+	, REGION_DEFAULT_STATE(0,0)
+	, _last_length (0)
+	, _last_position (0)
+        , _positional_lock_style (_type == DataType::AUDIO ? AudioTime : MusicTime)
+	, _first_edit (EditChangesNothing)
+	, _frozen (0)
+	, _read_data_count (0)
+	, _pending_changed (PropertyChange(0))
+	, _last_layer_op (0)
 	, _pending_explicit_relayer (false)
 {
-	register_states ();
+	const XMLProperty *prop;
+
+	register_properties ();
 
 	_sources.push_back (src);
 
+	if ((prop = node.property (X_("id")))) {
+		_id = prop->value();
+	}
+
 	if (set_state (node, Stateful::loading_state_version)) {
 		throw failed_constructor();
 	}
 
-	assert(_type != DataType::NIL);
-	assert(_sources.size() > 0);
+	assert (_type != DataType::NIL);
+	assert (_sources.size() > 0);
+	assert (_type == src->type());
 }
 
 Region::~Region ()
@@ -396,33 +516,6 @@ Region::~Region ()
 }
 
 void
-Region::copy_stuff (boost::shared_ptr<const Region> other, nframes_t /*offset*/, nframes_t length, const string& name, layer_t layer, Flag flags)
-{
-	_frozen = 0;
-	_pending_changed = Change (0);
-	_read_data_count = 0;
-	_valid_transients = false;
-
-	_length = length;
-	_last_length = length;
-	_sync_position = other->_sync_position;
-	_ancestral_start = other->_ancestral_start;
-	_ancestral_length = other->_ancestral_length;
-	_stretch = other->_stretch;
-	_shift = other->_shift;
-	_name = name;
-	_last_position = 0;
-	_position = 0;
-	_layer = layer;
-	_flags = Flag (flags & ~(Locked|WholeFile|Hidden));
-	_first_edit = EditChangesNothing;
-	_last_layer_op = 0;
-	_positional_lock_style = AudioTime;
-
-	use_sources (other->_sources);
-}
-
-void
 Region::set_playlist (boost::weak_ptr<Playlist> wpl)
 {
 	_playlist = wpl.lock();
@@ -441,10 +534,10 @@ Region::set_name (const std::string& str)
 }
 
 void
-Region::set_length (nframes_t len, void */*src*/)
+Region::set_length (framecnt_t len, void */*src*/)
 {
 	//cerr << "Region::set_length() len = " << len << endl;
-	if (_flags & Locked) {
+	if (locked()) {
 		return;
 	}
 
@@ -465,9 +558,7 @@ Region::set_length (nframes_t len, void */*src*/)
 
 		_last_length = _length;
 		_length = len;
-
-		_flags = Region::Flag (_flags & ~WholeFile);
-
+		_whole_file = false;
 		first_edit ();
 		maybe_uncopy ();
 		invalidate_transients ();
@@ -483,6 +574,7 @@ Region::set_length (nframes_t len, void */*src*/)
 void
 Region::maybe_uncopy ()
 {
+	/* this does nothing but marked a semantic moment once upon a time */
 }
 
 void
@@ -537,7 +629,7 @@ Region::move_to_natural_position (void *src)
 }
 
 void
-Region::special_set_position (nframes_t pos)
+Region::special_set_position (framepos_t pos)
 {
 	/* this is used when creating a whole file region as
 	   a way to store its "natural" or "captured" position.
@@ -574,12 +666,12 @@ Region::update_position_after_tempo_map_change ()
 	}
 
 	TempoMap& map (_session.tempo_map());
-	nframes_t pos = map.frame_time (_bbt_time);
+	framepos_t pos = map.frame_time (_bbt_time);
 	set_position_internal (pos, false);
 }
 
 void
-Region::set_position (nframes_t pos, void* /*src*/)
+Region::set_position (framepos_t pos, void* /*src*/)
 {
 	if (!can_move()) {
 		return;
@@ -589,7 +681,7 @@ Region::set_position (nframes_t pos, void* /*src*/)
 }
 
 void
-Region::set_position_internal (nframes_t pos, bool allow_bbt_recompute)
+Region::set_position_internal (framepos_t pos, bool allow_bbt_recompute)
 {
 	if (_position != pos) {
 		_last_position = _position;
@@ -621,9 +713,9 @@ Region::set_position_internal (nframes_t pos, bool allow_bbt_recompute)
 }
 
 void
-Region::set_position_on_top (nframes_t pos, void* /*src*/)
+Region::set_position_on_top (framepos_t pos, void* /*src*/)
 {
-	if (_flags & Locked) {
+	if (locked()) {
 		return;
 	}
 
@@ -654,9 +746,9 @@ Region::recompute_position_from_lock_style ()
 }
 
 void
-Region::nudge_position (nframes64_t n, void* /*src*/)
+Region::nudge_position (frameoffset_t n, void* /*src*/)
 {
-	if (_flags & Locked) {
+	if (locked()) {
 		return;
 	}
 
@@ -673,7 +765,7 @@ Region::nudge_position (nframes64_t n, void* /*src*/)
 			_position += n;
 		}
 	} else {
-		if (_position < (nframes_t) -n) {
+		if (_position < -n) {
 			_position = 0;
 		} else {
 			_position += n;
@@ -684,7 +776,7 @@ Region::nudge_position (nframes64_t n, void* /*src*/)
 }
 
 void
-Region::set_ancestral_data (nframes64_t s, nframes64_t l, float st, float sh)
+Region::set_ancestral_data (framepos_t s, framecnt_t l, float st, float sh)
 {
 	_ancestral_length = l;
 	_ancestral_start = s;
@@ -693,9 +785,9 @@ Region::set_ancestral_data (nframes64_t s, nframes64_t l, float st, float sh)
 }
 
 void
-Region::set_start (nframes_t pos, void* /*src*/)
+Region::set_start (framepos_t pos, void* /*src*/)
 {
-	if (_flags & (Locked|PositionLocked)) {
+	if (locked() || position_locked()) {
 		return;
 	}
 	/* This just sets the start, nothing else. It effectively shifts
@@ -710,7 +802,7 @@ Region::set_start (nframes_t pos, void* /*src*/)
 		}
 
 		_start = pos;
-		_flags = Region::Flag (_flags & ~WholeFile);
+		_whole_file = false;
 		first_edit ();
 		invalidate_transients ();
 
@@ -719,13 +811,13 @@ Region::set_start (nframes_t pos, void* /*src*/)
 }
 
 void
-Region::trim_start (nframes_t new_position, void */*src*/)
+Region::trim_start (framepos_t new_position, void */*src*/)
 {
-	if (_flags & (Locked|PositionLocked)) {
+	if (locked() || position_locked()) {
 		return;
 	}
-	nframes_t new_start;
-	int32_t start_shift;
+	framepos_t new_start;
+	frameoffset_t start_shift;
 
 	if (new_position > _position) {
 		start_shift = new_position - _position;
@@ -747,7 +839,7 @@ Region::trim_start (nframes_t new_position, void */*src*/)
 
 	} else if (start_shift < 0) {
 
-		if (_start < (nframes_t) -start_shift) {
+		if (_start < -start_shift) {
 			new_start = 0;
 		} else {
 			new_start = _start + start_shift;
@@ -761,21 +853,21 @@ Region::trim_start (nframes_t new_position, void */*src*/)
 	}
 
 	_start = new_start;
-	_flags = Region::Flag (_flags & ~WholeFile);
+	_whole_file = false;
 	first_edit ();
 
 	send_change (StartChanged);
 }
 
 void
-Region::trim_front (nframes_t new_position, void *src)
+Region::trim_front (framepos_t new_position, void *src)
 {
-	if (_flags & Locked) {
+	if (locked()) {
 		return;
 	}
 
-	nframes_t end = last_frame();
-	nframes_t source_zero;
+	framepos_t end = last_frame();
+	framepos_t source_zero;
 
 	if (_position > _start) {
 		source_zero = _position - _start;
@@ -785,7 +877,7 @@ Region::trim_front (nframes_t new_position, void *src)
 
 	if (new_position < end) { /* can't trim it zero or negative length */
 
-		nframes_t newlen;
+		framecnt_t newlen;
 
 		/* can't trim it back passed where source position zero is located */
 
@@ -810,9 +902,9 @@ Region::trim_front (nframes_t new_position, void *src)
  */
 
 void
-Region::trim_end (nframes_t new_endpoint, void */*src*/)
+Region::trim_end (framepos_t new_endpoint, void */*src*/)
 {
-	if (_flags & Locked) {
+	if (locked()) {
 		return;
 	}
 
@@ -825,9 +917,9 @@ Region::trim_end (nframes_t new_endpoint, void */*src*/)
 }
 
 void
-Region::trim_to (nframes_t position, nframes_t length, void *src)
+Region::trim_to (framepos_t position, framecnt_t length, void *src)
 {
-	if (_flags & Locked) {
+	if (locked()) {
 		return;
 	}
 
@@ -840,12 +932,12 @@ Region::trim_to (nframes_t position, nframes_t length, void *src)
 }
 
 void
-Region::trim_to_internal (nframes_t position, nframes_t length, void */*src*/)
+Region::trim_to_internal (framepos_t position, framecnt_t length, void */*src*/)
 {
-	int32_t start_shift;
-	nframes_t new_start;
+	frameoffset_t start_shift;
+	framepos_t new_start;
 
-	if (_flags & Locked) {
+	if (locked()) {
 		return;
 	}
 
@@ -866,7 +958,7 @@ Region::trim_to_internal (nframes_t position, nframes_t length, void */*src*/)
 
 	} else if (start_shift < 0) {
 
-		if (_start < (nframes_t) -start_shift) {
+		if (_start < -start_shift) {
 			new_start = 0;
 		} else {
 			new_start = _start + start_shift;
@@ -879,28 +971,28 @@ Region::trim_to_internal (nframes_t position, nframes_t length, void */*src*/)
 		return;
 	}
 
-	Change what_changed = Change (0);
+	PropertyChange what_changed = PropertyChange (0);
 
 	if (_start != new_start) {
 		_start = new_start;
-		what_changed = Change (what_changed|StartChanged);
+		what_changed = PropertyChange (what_changed|StartChanged);
 	}
 	if (_length != length) {
 		if (!_frozen) {
 			_last_length = _length;
 		}
 		_length = length;
-		what_changed = Change (what_changed|LengthChanged);
+		what_changed = PropertyChange (what_changed|LengthChanged);
 	}
 	if (_position != position) {
 		if (!_frozen) {
 			_last_position = _position;
 		}
 		_position = position;
-		what_changed = Change (what_changed|PositionChanged);
+		what_changed = PropertyChange (what_changed|PositionChanged);
 	}
 
-	_flags = Region::Flag (_flags & ~WholeFile);
+	_whole_file = false;
 
 	if (what_changed & (StartChanged|LengthChanged)) {
 		first_edit ();
@@ -915,28 +1007,30 @@ void
 Region::set_hidden (bool yn)
 {
 	if (hidden() != yn) {
-
-		if (yn) {
-			_flags = Flag (_flags|Hidden);
-		} else {
-			_flags = Flag (_flags & ~Hidden);
-		}
-
+		_hidden = yn;
 		send_change (HiddenChanged);
 	}
 }
 
 void
-Region::set_muted (bool yn)
+Region::set_whole_file (bool yn)
 {
-	if (muted() != yn) {
+	_whole_file = yn;
+	/* no change signal */
+}
 
-		if (yn) {
-			_flags = Flag (_flags|Muted);
-		} else {
-			_flags = Flag (_flags & ~Muted);
-		}
+void
+Region::set_automatic (bool yn)
+{
+	_automatic = yn;
+	/* no change signal */
+}
 
+void
+Region::set_muted (bool yn)
+{
+	if (muted() != yn) {
+		_muted = yn;
 		send_change (MuteChanged);
 	}
 }
@@ -945,11 +1039,7 @@ void
 Region::set_opaque (bool yn)
 {
 	if (opaque() != yn) {
-		if (yn) {
-			_flags = Flag (_flags|Opaque);
-		} else {
-			_flags = Flag (_flags & ~Opaque);
-		}
+		_opaque = yn;
 		send_change (OpacityChanged);
 	}
 }
@@ -958,11 +1048,7 @@ void
 Region::set_locked (bool yn)
 {
 	if (locked() != yn) {
-		if (yn) {
-			_flags = Flag (_flags|Locked);
-		} else {
-			_flags = Flag (_flags & ~Locked);
-		}
+		_locked = yn;
 		send_change (LockChanged);
 	}
 }
@@ -971,25 +1057,19 @@ void
 Region::set_position_locked (bool yn)
 {
 	if (position_locked() != yn) {
-		if (yn) {
-			_flags = Flag (_flags|PositionLocked);
-		} else {
-			_flags = Flag (_flags & ~PositionLocked);
-		}
+		_position_locked = yn;
 		send_change (LockChanged);
 	}
 }
 
 void
-Region::set_sync_position (nframes_t absolute_pos)
+Region::set_sync_position (framepos_t absolute_pos)
 {
-	nframes_t const file_pos = _start + (absolute_pos - _position);
+	framepos_t const file_pos = _start + (absolute_pos - _position);
 
 	if (file_pos != _sync_position) {
-
+		_sync_marked = true;
 		_sync_position = file_pos;
-		_flags = Flag (_flags|SyncMarked);
-
 		if (!_frozen) {
 			maybe_uncopy ();
 		}
@@ -1000,9 +1080,8 @@ Region::set_sync_position (nframes_t absolute_pos)
 void
 Region::clear_sync_position ()
 {
-	if (_flags & SyncMarked) {
-		_flags = Flag (_flags & ~SyncMarked);
-
+	if (sync_marked()) {
+		_sync_marked = false;
 		if (!_frozen) {
 			maybe_uncopy ();
 		}
@@ -1010,12 +1089,12 @@ Region::clear_sync_position ()
 	}
 }
 
-nframes_t
+framepos_t
 Region::sync_offset (int& dir) const
 {
 	/* returns the sync point relative the first frame of the region */
 
-	if (_flags & SyncMarked) {
+	if (sync_marked()) {
 		if (_sync_position > _start) {
 			dir = 1;
 			return _sync_position - _start;
@@ -1029,11 +1108,11 @@ Region::sync_offset (int& dir) const
 	}
 }
 
-nframes_t
-Region::adjust_to_sync (nframes_t pos) const
+framepos_t
+Region::adjust_to_sync (framepos_t pos) const
 {
 	int sync_dir;
-	nframes_t offset = sync_offset (sync_dir);
+	frameoffset_t offset = sync_offset (sync_dir);
 
 	// cerr << "adjusting pos = " << pos << " to sync at " << _sync_position << " offset = " << offset << " with dir = " << sync_dir << endl;
 
@@ -1052,10 +1131,10 @@ Region::adjust_to_sync (nframes_t pos) const
 	return pos;
 }
 
-nframes_t
+framepos_t
 Region::sync_position() const
 {
-	if (_flags & SyncMarked) {
+	if (sync_marked()) {
 		return _sync_position;
 	} else {
 		return _start;
@@ -1116,7 +1195,7 @@ Region::state (bool /*full_state*/)
 	char buf[64];
 	const char* fe = NULL;
 
-	add_states (*node);
+	add_properties (*node);
 
 	_id.print (buf, sizeof (buf));
 	node->add_property ("id", buf);
@@ -1158,19 +1237,21 @@ Region::get_state ()
 }
 
 int
-Region::set_live_state (const XMLNode& node, int /*version*/, Change& what_changed, bool send)
+Region::set_state (const XMLNode& node, int version)
 {
-	const XMLNodeList& nlist = node.children();
-	const XMLProperty *prop;
+	PropertyChange what_changed = PropertyChange (0);
+	return _set_state (node, version, what_changed, true);
+}
 
-	/* this is responsible for setting those aspects of Region state
-	   that are mutable after construction.
-	*/
+int
+Region::_set_state (const XMLNode& node, int version, PropertyChange& what_changed, bool send)
+{
+	const XMLProperty* prop;
 
-	if ((prop = node.property ("type")) == 0) {
-		_type = DataType::AUDIO;
-	} else {
-		_type = DataType(prop->value());
+	what_changed = set_properties (node);
+
+	if ((prop = node.property (X_("id")))) {
+		_id = prop->value();
 	}
 
 	if ((prop = node.property ("positional-lock-style")) != 0) {
@@ -1192,8 +1273,6 @@ Region::set_live_state (const XMLNode& node, int /*version*/, Change& what_chang
 
 	}
 
-	/* XXX FIRST EDIT !!! */
-
 	/* fix problems with old sessions corrupted by impossible
 	   values for _stretch or _shift
 	*/
@@ -1205,7 +1284,7 @@ Region::set_live_state (const XMLNode& node, int /*version*/, Change& what_chang
 		_shift = 1.0f;
 	}
 
-	/* note: derived classes set flags */
+	const XMLNodeList& nlist = node.children();
 
 	for (XMLNodeConstIterator niter = nlist.begin(); niter != nlist.end(); ++niter) {
 
@@ -1228,47 +1307,6 @@ Region::set_live_state (const XMLNode& node, int /*version*/, Change& what_chang
 	return 0;
 }
 
-int
-Region::set_state (const XMLNode& node, int version)
-{
-	const XMLProperty *prop;
-
-	/* ID is not allowed to change, ever */
-
-	if ((prop = node.property ("id"))) {
-		_id = prop->value();
-	}
-
-	_first_edit = EditChangesNothing;
-
-	uint32_t old_flags = _flags;
-
-	Change what_changed = set_state_using_states (node);
-
-	/* leave this flag setting in place, no matter what */
-
-	if ((old_flags & DoNotSendPropertyChanges)) {
-		_flags = Flag (_flags | DoNotSendPropertyChanges);
-	}
-
-	if ((old_flags ^ _flags) & Muted) {
-		what_changed = Change (what_changed|MuteChanged);
-		cerr << _name << " mute changed\n";
-	}
-	if ((old_flags ^ _flags) & Opaque) {
-		what_changed = Change (what_changed|OpacityChanged);
-		cerr << _name << " opacity changed\n";
-	}
-	if ((old_flags ^ _flags) & Locked) {
-		what_changed = Change (what_changed|LockChanged);
-		cerr << _name << " lock changed\n";
-	}
-
-	set_live_state (node, version, what_changed, true);
-
-	return 0;
-}
-
 void
 Region::freeze ()
 {
@@ -1280,7 +1318,7 @@ Region::freeze ()
 void
 Region::thaw ()
 {
-	Change what_changed = Change (0);
+	PropertyChange what_changed = PropertyChange (0);
 
 	{
 		Glib::Mutex::Lock lm (_lock);
@@ -1291,11 +1329,11 @@ Region::thaw ()
 
 		if (_pending_changed) {
 			what_changed = _pending_changed;
-			_pending_changed = Change (0);
+			_pending_changed = PropertyChange (0);
 		}
 	}
 
-	if (what_changed == Change (0)) {
+	if (what_changed == PropertyChange (0)) {
 		return;
 	}
 
@@ -1310,13 +1348,13 @@ Region::thaw ()
 }
 
 void
-Region::send_change (Change what_changed)
+Region::send_change (PropertyChange what_changed)
 {
 
 	{
 		Glib::Mutex::Lock lm (_lock);
 		if (_frozen) {
-			_pending_changed = Change (_pending_changed|what_changed);
+			_pending_changed = PropertyChange (_pending_changed|what_changed);
 			return;
 		}
 	}
@@ -1325,8 +1363,8 @@ Region::send_change (Change what_changed)
 	StateChanged (what_changed);
 	cerr << _name << " done with " << hex << what_changed << dec << " @" << get_microseconds() << endl;
 
-	if (!(_flags & DoNotSendPropertyChanges)) {
-
+	if (!_no_property_changes) {
+		
 		/* Try and send a shared_pointer unless this is part of the constructor.
 		   If so, do nothing.
 		*/
@@ -1457,16 +1495,16 @@ Region::source_length(uint32_t n) const
 }
 
 bool
-Region::verify_length (nframes_t len)
+Region::verify_length (framecnt_t len)
 {
 	if (source() && (source()->destructive() || source()->length_mutable())) {
 		return true;
 	}
 
-	nframes_t maxlen = 0;
+	framecnt_t maxlen = 0;
 
 	for (uint32_t n=0; n < _sources.size(); ++n) {
-		maxlen = max (maxlen, (nframes_t)source_length(n) - _start);
+		maxlen = max (maxlen, source_length(n) - _start);
 	}
 
 	len = min (len, maxlen);
@@ -1475,16 +1513,16 @@ Region::verify_length (nframes_t len)
 }
 
 bool
-Region::verify_start_and_length (nframes_t new_start, nframes_t& new_length)
+Region::verify_start_and_length (framepos_t new_start, framecnt_t& new_length)
 {
 	if (source() && (source()->destructive() || source()->length_mutable())) {
 		return true;
 	}
 
-	nframes_t maxlen = 0;
+	framecnt_t maxlen = 0;
 
 	for (uint32_t n=0; n < _sources.size(); ++n) {
-		maxlen = max (maxlen, (nframes_t)source_length(n) - new_start);
+		maxlen = max (maxlen, source_length(n) - new_start);
 	}
 
 	new_length = min (new_length, maxlen);
@@ -1493,7 +1531,7 @@ Region::verify_start_and_length (nframes_t new_start, nframes_t& new_length)
 }
 
 bool
-Region::verify_start (nframes_t pos)
+Region::verify_start (framepos_t pos)
 {
 	if (source() && (source()->destructive() || source()->length_mutable())) {
 		return true;
@@ -1508,7 +1546,7 @@ Region::verify_start (nframes_t pos)
 }
 
 bool
-Region::verify_start_mutable (nframes_t& new_start)
+Region::verify_start_mutable (framepos_t& new_start)
 {
 	if (source() && (source()->destructive() || source()->length_mutable())) {
 		return true;
@@ -1573,3 +1611,113 @@ Region::use_sources (SourceList const & s)
 	}
 }
 
+
+PropertyChange
+Region::set_property (const PropertyBase& prop)
+{
+	PropertyChange c = PropertyChange (0);
+
+	DEBUG_TRACE (DEBUG::Properties,  string_compose ("region %1 set property %2\n", _name.val(), prop.property_name()));
+
+	if (prop == Properties::muted.id) {
+		bool val = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+		if (val != _muted) {
+			DEBUG_TRACE (DEBUG::Properties, string_compose ("region %1 muted changed from %2 to %3",
+									_name.val(), _muted.val(), val));
+			_muted = val;
+			c = MuteChanged;
+		}
+	} else if (prop == Properties::opaque.id) {
+		bool val = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+		if (val != _opaque) {
+			DEBUG_TRACE (DEBUG::Properties, string_compose ("region %1 opaque changed from %2 to %3",
+									_name.val(), _opaque.val(), val));
+			_opaque = val;
+			c = OpacityChanged;
+		}
+	} else if (prop == Properties::locked.id) {
+		bool val = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+		if (val != _locked) {
+			DEBUG_TRACE (DEBUG::Properties, string_compose ("region %1 locked changed from %2 to %3",
+									_name.val(), _locked.val(), val));
+			_locked = val;
+			c = LockChanged;
+		}
+	} else if (prop == Properties::automatic.id) {
+		_automatic = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+	} else if (prop == Properties::whole_file.id) {
+		_whole_file = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+	} else if (prop == Properties::import.id) {
+		_import = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+	} else if (prop == Properties::external.id) {
+		_external = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+	} else if (prop == Properties::sync_marked.id) {
+		_sync_marked = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+	} else if (prop == Properties::left_of_split.id) {
+		_left_of_split = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+	} else if (prop == Properties::right_of_split.id) {
+		_right_of_split = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+	} else if (prop == Properties::hidden.id) {
+		bool val = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+		if (val != _hidden) {
+			_hidden = val;
+			c = HiddenChanged;
+		}
+	} else if (prop == Properties::position_locked.id) {
+		_position_locked = dynamic_cast<const PropertyTemplate<bool>*>(&prop)->val();
+	} else if (prop == Properties::start.id) {
+		_start = dynamic_cast<const PropertyTemplate<framepos_t>*>(&prop)->val();
+	} else if (prop == Properties::length.id) {
+		const PropertyTemplate<framecnt_t>* pt1 = dynamic_cast<const PropertyTemplate<framecnt_t>* >(&prop);
+		const PropertyTemplate<int>* pt2 = dynamic_cast<const PropertyTemplate<int>* >(&prop);
+		
+		cerr << "Cast to frmecnt = " << pt1 << " to int = " << pt2 << endl;
+
+		framecnt_t val = dynamic_cast<const PropertyTemplate<framecnt_t>* > (&prop)->val();
+		if (val != _length) {
+			DEBUG_TRACE (DEBUG::Properties, string_compose ("region %1 length changed from %2 to %3",
+									_name.val(), _length.val(), val));
+			_length = val;
+			c = LengthChanged;
+		} else {
+			DEBUG_TRACE (DEBUG::Properties, string_compose ("length %1 matches %2\n", _length.val(), val));
+		}
+
+	} else if (prop == Properties::position.id) {
+		framepos_t val = dynamic_cast<const PropertyTemplate<framepos_t>*>(&prop)->val();
+		if (val != _position) {
+			DEBUG_TRACE (DEBUG::Properties, string_compose ("region %1 position changed from %2 to %3",
+									_name.val(), _position.val(), val));
+			_position = val;
+			c = PositionChanged;
+		}
+	} else if (prop == Properties::sync_position.id) {
+		framepos_t val = dynamic_cast<const PropertyTemplate<framepos_t>*>(&prop)->val();
+		if (val != _sync_position) {
+			DEBUG_TRACE (DEBUG::Properties, string_compose ("region %1 syncpos changed from %2 to %3",
+									_name.val(), _sync_position, val));
+			_sync_position = val;
+			c = SyncOffsetChanged;
+		}
+	} else if (prop == Properties::layer.id) {
+		layer_t val = dynamic_cast<const PropertyTemplate<layer_t>*>(&prop)->val();
+		if (val != _layer) {
+			DEBUG_TRACE (DEBUG::Properties, string_compose ("region %1 syncpos changed from %2 to %3",
+									_name.val(), _sync_position, val));
+			_layer = val;
+			c = LayerChanged;
+		}
+	} else if (prop == Properties::ancestral_start.id) {
+		_ancestral_start = dynamic_cast<const PropertyTemplate<framepos_t>*>(&prop)->val();
+	} else if (prop == Properties::ancestral_length.id) {
+		_ancestral_length = dynamic_cast<const PropertyTemplate<framecnt_t>*>(&prop)->val();
+	} else if (prop == Properties::stretch.id) {
+		_stretch = dynamic_cast<const PropertyTemplate<float>*>(&prop)->val();
+	} else if (prop == Properties::shift.id) {
+		_shift = dynamic_cast<const PropertyTemplate<float>*>(&prop)->val();
+	} else {
+		return SessionObject::set_property (prop);
+	}
+	
+	return c;
+}
diff --git a/libs/ardour/region_command.cc b/libs/ardour/region_command.cc
index 02a542e6c7..3e2bba51b0 100644
--- a/libs/ardour/region_command.cc
+++ b/libs/ardour/region_command.cc
@@ -4,7 +4,6 @@
 #include "pbd/enumwriter.h"
 
 #include "ardour/region.h"
-#include "ardour/region_command.h"
 #include "ardour/utils.h"
 
 #include "i18n.h"
diff --git a/libs/ardour/region_factory.cc b/libs/ardour/region_factory.cc
index 273066855b..652354b7fa 100644
--- a/libs/ardour/region_factory.cc
+++ b/libs/ardour/region_factory.cc
@@ -38,82 +38,136 @@ PBD::Signal1<void,boost::shared_ptr<Region> > RegionFactory::CheckNewRegion;
 map<PBD::ID,boost::weak_ptr<Region> > RegionFactory::region_map;
 
 boost::shared_ptr<Region>
-RegionFactory::create (boost::shared_ptr<Region> region, nframes_t start,
-		       nframes_t length, const std::string& name,
-		       layer_t layer, Region::Flag flags, bool announce)
+RegionFactory::create (boost::shared_ptr<const Region> region)
+{
+	boost::shared_ptr<Region> ret;
+	boost::shared_ptr<const AudioRegion> ar;
+	boost::shared_ptr<const MidiRegion> mr;
+
+	if ((ar = boost::dynamic_pointer_cast<const AudioRegion>(region)) != 0) {
+
+		AudioRegion* arn = new AudioRegion (ar, 0, true);
+		boost_debug_shared_ptr_mark_interesting (arn, "Region");
+
+		boost::shared_ptr<AudioRegion> arp (arn);
+		ret = boost::static_pointer_cast<Region> (arp);
+
+	} else if ((mr = boost::dynamic_pointer_cast<const MidiRegion>(region)) != 0) {
+
+		MidiRegion* mrn = new MidiRegion (mr, 0, true);
+		boost::shared_ptr<MidiRegion> mrp (mrn);
+		ret = boost::static_pointer_cast<Region> (mrp);
+
+	} else {
+		fatal << _("programming error: RegionFactory::create() called with unknown Region type")
+		      << endmsg;
+		/*NOTREACHED*/
+	}
+
+	if (ret) {
+		ret->unlock_property_changes ();
+		map_add (ret);
+
+		/* pure copy constructor - no property list */
+		/* pure copy constructor - no CheckNewRegion emitted */
+	}
+
+	return ret;
+}
+
+boost::shared_ptr<Region>
+RegionFactory::create (boost::shared_ptr<Region> region, frameoffset_t offset, const PropertyList& plist, bool announce)
 {
+	boost::shared_ptr<Region> ret;
 	boost::shared_ptr<const AudioRegion> other_a;
 	boost::shared_ptr<const MidiRegion> other_m;
 
 	if ((other_a = boost::dynamic_pointer_cast<AudioRegion>(region)) != 0) {
-		AudioRegion* ar = new AudioRegion (other_a, start, length, name, layer, flags);
+
+		AudioRegion* ar = new AudioRegion (other_a, offset, true);
 		boost_debug_shared_ptr_mark_interesting (ar, "Region");
+
 		boost::shared_ptr<AudioRegion> arp (ar);
-		boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (arp));
-		ret->unlock_property_changes ();
-		map_add (ret);
-		if (announce) {
-			CheckNewRegion (ret);
-		}
-		return ret;
+		ret = boost::static_pointer_cast<Region> (arp);
+
 	} else if ((other_m = boost::dynamic_pointer_cast<MidiRegion>(region)) != 0) {
-		MidiRegion* ar = new MidiRegion (other_m, start, length, name, layer, flags);
-		boost::shared_ptr<MidiRegion> arp (ar);
-		boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (arp));
-		ret->unlock_property_changes ();
-		map_add (ret);
-		if (announce) {
-			CheckNewRegion (ret);
-		}
-		return ret;
+
+		MidiRegion* mr = new MidiRegion (other_m, offset, true);
+		boost::shared_ptr<MidiRegion> mrp (mr);
+		ret = boost::static_pointer_cast<Region> (mrp);
+
 	} else {
 		fatal << _("programming error: RegionFactory::create() called with unknown Region type")
 		      << endmsg;
 		/*NOTREACHED*/
 		return boost::shared_ptr<Region>();
 	}
+
+	if (ret) {
+
+		ret->set_properties (plist);
+		ret->unlock_property_changes ();
+
+		map_add (ret);
+
+		if (announce) {
+			CheckNewRegion (ret);
+		}
+	}
+
+	return ret;
 }
 
 boost::shared_ptr<Region>
-RegionFactory::create (boost::shared_ptr<const Region> region)
+RegionFactory::create (boost::shared_ptr<Region> region, const PropertyList& plist, bool announce)
 {
-	boost::shared_ptr<const AudioRegion> ar;
-	boost::shared_ptr<const MidiRegion> mr;
+	boost::shared_ptr<Region> ret;
+	boost::shared_ptr<const AudioRegion> other_a;
+	boost::shared_ptr<const MidiRegion> other_m;
+
+	if ((other_a = boost::dynamic_pointer_cast<AudioRegion>(region)) != 0) {
+
+		AudioRegion* ar = new AudioRegion (other_a, 0, false);
+		boost_debug_shared_ptr_mark_interesting (ar, "Region");
+
+		boost::shared_ptr<AudioRegion> arp (ar);
+		ret = boost::static_pointer_cast<Region> (arp);
+
+	} else if ((other_m = boost::dynamic_pointer_cast<MidiRegion>(region)) != 0) {
+
+		MidiRegion* mr = new MidiRegion (other_m, 0, false);
+		boost::shared_ptr<MidiRegion> mrp (mr);
+		ret = boost::static_pointer_cast<Region> (mrp);
 
-	if ((ar = boost::dynamic_pointer_cast<const AudioRegion>(region)) != 0) {
-		AudioRegion* arn = new AudioRegion (ar);
-		boost_debug_shared_ptr_mark_interesting (arn, "Region");
-		boost::shared_ptr<Region> ret (arn);
-		ret->unlock_property_changes ();
-		map_add (ret);
-		/* pure copy constructor - no CheckNewRegion emitted */
-		return ret;
-	} else if ((mr = boost::dynamic_pointer_cast<const MidiRegion>(region)) != 0) {
-		boost::shared_ptr<Region> ret (new MidiRegion (mr));
-		ret->unlock_property_changes ();
-		/* pure copy constructor - no CheckNewRegion emitted */
-		return ret;
 	} else {
 		fatal << _("programming error: RegionFactory::create() called with unknown Region type")
 		      << endmsg;
 		/*NOTREACHED*/
 		return boost::shared_ptr<Region>();
 	}
-}
 
-boost::shared_ptr<Region>
-RegionFactory::create (boost::shared_ptr<AudioRegion> region, nframes_t start,
-		       nframes_t length, const std::string& name,
-		       layer_t layer, Region::Flag flags, bool announce)
-{
-	return create (boost::static_pointer_cast<Region> (region), start, length, name, layer, flags, announce);
+	if (ret) {
+
+		ret->set_properties (plist);
+		ret->unlock_property_changes ();
+
+		map_add (ret);
+
+		if (announce) {
+			CheckNewRegion (ret);
+		}
+	}
+
+	return ret;
 }
 
-boost::shared_ptr<Region>
-RegionFactory::create (boost::shared_ptr<Region> region, const SourceList& srcs,
-		       const std::string& name, layer_t layer, Region::Flag flags, bool announce)
 
+
+
+boost::shared_ptr<Region>
+RegionFactory::create (boost::shared_ptr<Region> region, const SourceList& srcs, const PropertyList& plist, bool announce)
 {
+	boost::shared_ptr<Region> ret;
 	boost::shared_ptr<const AudioRegion> other;
 
 	/* used by AudioFilter when constructing a new region that is intended to have nearly
@@ -121,130 +175,165 @@ RegionFactory::create (boost::shared_ptr<Region> region, const SourceList& srcs,
 	*/
 
 	if ((other = boost::dynamic_pointer_cast<AudioRegion>(region)) != 0) {
-		AudioRegion* ar = new AudioRegion (other, srcs, srcs.front()->length(srcs.front()->timeline_position()), name, layer, flags);
+
+		// XXX use me in caller where plist is setup, this is start i think srcs.front()->length (srcs.front()->timeline_position())
+		
+		AudioRegion* ar = new AudioRegion (other, srcs);
 		boost_debug_shared_ptr_mark_interesting (ar, "Region");
+
 		boost::shared_ptr<AudioRegion> arp (ar);
-		boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (arp));
-		ret->unlock_property_changes ();
-		map_add (ret);
-		if (announce) {
-			CheckNewRegion (ret);
-		}
-		return ret;
+		ret = boost::static_pointer_cast<Region> (arp);
+
 	} else {
 		fatal << _("programming error: RegionFactory::create() called with unknown Region type")
 		      << endmsg;
 		/*NOTREACHED*/
-		return boost::shared_ptr<Region>();
 	}
-}
 
-boost::shared_ptr<Region>
-RegionFactory::create (Session& session, XMLNode& node, bool yn)
-{
-	boost::shared_ptr<Region> r = session.XMLRegionFactory (node, yn);
+	if (ret) {
 
-	if (r) {
-		r->unlock_property_changes ();
-		map_add (r);
-		CheckNewRegion (r);
+		ret->set_properties (plist);
+		ret->unlock_property_changes ();
+
+		map_add (ret);
+
+		if (announce) {
+			CheckNewRegion (ret);
+		}
 	}
 
-	return r;
+	return ret;
+
 }
 
 boost::shared_ptr<Region>
-RegionFactory::create (const SourceList& srcs, nframes_t start, nframes_t length, const string& name, layer_t layer, Region::Flag flags, bool announce)
+RegionFactory::create (boost::shared_ptr<Source> src, const PropertyList& plist, bool announce)
 {
-	if (srcs.empty()) {
-		return boost::shared_ptr<Region>();
-	}
+	boost::shared_ptr<Region> ret; 
+	boost::shared_ptr<AudioSource> as;
+	boost::shared_ptr<MidiSource> ms;
 
-	if (srcs[0]->type() == DataType::AUDIO) {
+	if ((as = boost::dynamic_pointer_cast<AudioSource>(src)) != 0) {
 
-		AudioRegion* ar = new AudioRegion (srcs, start, length, name, layer, flags);
+		AudioRegion* ar = new AudioRegion (as);
 		boost_debug_shared_ptr_mark_interesting (ar, "Region");
+
 		boost::shared_ptr<AudioRegion> arp (ar);
-		boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (arp));
+		ret = boost::static_pointer_cast<Region> (arp);
+
+	} else if ((ms = boost::dynamic_pointer_cast<MidiSource>(src)) != 0) {
+		MidiRegion* mr = new MidiRegion (ms);
+		boost_debug_shared_ptr_mark_interesting (mr, "Region");
+
+		boost::shared_ptr<MidiRegion> mrp (mr);
+		ret = boost::static_pointer_cast<Region> (mrp);
+	}
+
+	if (ret) {
+		ret->set_properties (plist);
 		ret->unlock_property_changes ();
+
 		map_add (ret);
+
 		if (announce) {
 			CheckNewRegion (ret);
 		}
-		return ret;
+	}
 
-	} else if (srcs[0]->type() == DataType::MIDI) {
+	return ret;
+}
 
-		MidiRegion* ar = new MidiRegion (srcs, start, length, name, layer, flags);
-		boost::shared_ptr<MidiRegion> mrp (ar);
-		boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (mrp));
+boost::shared_ptr<Region>
+RegionFactory::create (const SourceList& srcs, const PropertyList& plist, bool announce)
+{
+	boost::shared_ptr<Region> ret; 
+	boost::shared_ptr<AudioSource> as;
+	boost::shared_ptr<MidiSource> ms;
+
+	if ((as = boost::dynamic_pointer_cast<AudioSource>(srcs[0])) != 0) {
+
+		AudioRegion* ar = new AudioRegion (srcs);
+		boost_debug_shared_ptr_mark_interesting (ar, "Region");
+
+		boost::shared_ptr<AudioRegion> arp (ar);
+		ret = boost::static_pointer_cast<Region> (arp);
+
+	} else if ((ms = boost::dynamic_pointer_cast<MidiSource>(srcs[0])) != 0) {
+		MidiRegion* mr = new MidiRegion (srcs);
+		boost_debug_shared_ptr_mark_interesting (mr, "Region");
+
+		boost::shared_ptr<MidiRegion> mrp (mr);
+		ret = boost::static_pointer_cast<Region> (mrp);
+	}
+
+	if (ret) {
+		ret->set_properties (plist);
 		ret->unlock_property_changes ();
+
 		map_add (ret);
+
 		if (announce) {
 			CheckNewRegion (ret);
 		}
-		return ret;
+	}
 
+	return ret;
+}
+
+boost::shared_ptr<Region>
+RegionFactory::create (Session& session, XMLNode& node, bool yn)
+{
+	boost::shared_ptr<Region> r = session.XMLRegionFactory (node, yn);
+
+	if (r) {
+		r->unlock_property_changes ();
+		map_add (r);
+		CheckNewRegion (r);
 	}
 
-	return boost::shared_ptr<Region> ();
+	return r;
 }
 
+
 boost::shared_ptr<Region>
 RegionFactory::create (SourceList& srcs, const XMLNode& node)
 {
+	boost::shared_ptr<Region> ret;
+
 	if (srcs.empty()) {
-		return boost::shared_ptr<Region>();
+		return ret;
 	}
 
 	if (srcs[0]->type() == DataType::AUDIO) {
+
 		AudioRegion* ar = new AudioRegion (srcs, node);
 		boost_debug_shared_ptr_mark_interesting (ar, "Region");
+
+		boost::shared_ptr<AudioRegion> arp (ar);
+		ret = boost::static_pointer_cast<Region> (arp);
+
 		boost::shared_ptr<Region> ret (ar);
-		ret->unlock_property_changes ();
-		map_add (ret);
-		CheckNewRegion (ret);
-		return ret;
-	} else if (srcs[0]->type() == DataType::MIDI) {
-		boost::shared_ptr<Region> ret (new MidiRegion (srcs, node));
-		ret->unlock_property_changes ();
-		map_add (ret);
-		CheckNewRegion (ret);
+
 		return ret;
-	}
 
-	return boost::shared_ptr<Region> ();
-}
+	} else if (srcs[0]->type() == DataType::MIDI) {
+		
+		MidiRegion* mr = new MidiRegion (srcs, node);
 
-boost::shared_ptr<Region>
-RegionFactory::create (boost::shared_ptr<Source> src, nframes_t start, nframes_t length, const string& name, layer_t layer, Region::Flag flags, bool announce)
-{
-	boost::shared_ptr<AudioSource> as;
-	boost::shared_ptr<MidiSource> ms;
+		boost::shared_ptr<MidiRegion> mrp (mr);
+		ret = boost::static_pointer_cast<Region> (mrp);
+	}
 
-	if ((as = boost::dynamic_pointer_cast<AudioSource>(src)) != 0) {
-		AudioRegion* ar = new AudioRegion (as, start, length, name, layer, flags);
-		boost_debug_shared_ptr_mark_interesting (ar, "Region");
-		boost::shared_ptr<Region> ret (ar);
+	if (ret) {
 		ret->unlock_property_changes ();
 		map_add (ret);
-		if (announce) {
-			CheckNewRegion (ret);
-		}
-		return ret;
-	} else if ((ms = boost::dynamic_pointer_cast<MidiSource>(src)) != 0) {
-		boost::shared_ptr<Region> ret (new MidiRegion (ms, start, length, name, layer, flags));
-		ret->unlock_property_changes ();
-		map_add (ret);
-		if (announce) {
-			CheckNewRegion (ret);
-		}
-		return ret;
+		CheckNewRegion (ret);
 	}
 
-	return boost::shared_ptr<Region>();
+	return ret;
 }
 
+
 void
 RegionFactory::map_add (boost::shared_ptr<Region> r)
 {
diff --git a/libs/ardour/reverse.cc b/libs/ardour/reverse.cc
index a35858ce97..10fce58442 100644
--- a/libs/ardour/reverse.cc
+++ b/libs/ardour/reverse.cc
@@ -46,11 +46,11 @@ Reverse::run (boost::shared_ptr<Region> r)
 {
 	SourceList nsrcs;
 	SourceList::iterator si;
-	nframes_t blocksize = 256 * 1024;
+	framecnt_t blocksize = 256 * 1024;
 	Sample* buf = 0;
-	nframes_t fpos;
-	nframes_t fstart;
-	nframes_t to_read;
+	framepos_t fpos;
+	framepos_t fstart;
+	framecnt_t to_read;
 	int ret = -1;
 
 	boost::shared_ptr<AudioRegion> region = boost::dynamic_pointer_cast<AudioRegion>(r);
diff --git a/libs/ardour/route.cc b/libs/ardour/route.cc
index 0cf62f4cae..34274832c1 100644
--- a/libs/ardour/route.cc
+++ b/libs/ardour/route.cc
@@ -281,7 +281,7 @@ Route::inc_gain (gain_t fraction, void *src)
 void
 Route::set_gain (gain_t val, void *src)
 {
-	if (src != 0 && _route_group && src != _route_group && _route_group->active_property (RouteGroup::Gain)) {
+	if (src != 0 && _route_group && src != _route_group && _route_group->is_active() && _route_group->is_gain()) {
 
 		if (_route_group->is_relative()) {
 
@@ -563,7 +563,7 @@ Route::set_solo (bool yn, void *src)
 		return;
 	}
 
-	if (_route_group && src != _route_group && _route_group->active_property (RouteGroup::Solo)) {
+	if (_route_group && src != _route_group && _route_group->is_active() && _route_group->is_solo()) {
 		_route_group->apply (&Route::set_solo, yn, _route_group);
 		return;
 	}
@@ -624,7 +624,7 @@ Route::set_solo_isolated (bool yn, void *src)
 		return;
 	}
 
-	if (_route_group && src != _route_group && _route_group->active_property (RouteGroup::Solo)) {
+	if (_route_group && src != _route_group && _route_group->is_active() && _route_group->is_solo()) {
 		_route_group->apply (&Route::set_solo_isolated, yn, _route_group);
 		return;
 	}
@@ -682,7 +682,7 @@ Route::set_mute_points (MuteMaster::MutePoint mp)
 void
 Route::set_mute (bool yn, void *src)
 {
-	if (_route_group && src != _route_group && _route_group->active_property (RouteGroup::Mute)) {
+	if (_route_group && src != _route_group && _route_group->is_active() && _route_group->is_mute()) {
 		_route_group->apply (&Route::set_mute, yn, _route_group);
 		return;
 	}
diff --git a/libs/ardour/route_group.cc b/libs/ardour/route_group.cc
index e1d43f4cd6..5b998d22f7 100644
--- a/libs/ardour/route_group.cc
+++ b/libs/ardour/route_group.cc
@@ -37,15 +37,65 @@
 #include "i18n.h"
 
 using namespace ARDOUR;
+using namespace PBD;
 using namespace std;
 
-RouteGroup::RouteGroup (Session& s, const string &n, Flag f, Property p)
-	: _session (s)
+PropertyChange RouteGroup::FlagsChange = new_change ();
+PropertyChange RouteGroup::PropertiesChange = new_change ();
+
+namespace ARDOUR {
+	namespace Properties {
+		PropertyDescriptor<bool> relative;
+		PropertyDescriptor<bool> active;
+		PropertyDescriptor<bool> gain;
+		PropertyDescriptor<bool> mute;
+		PropertyDescriptor<bool> solo;
+		PropertyDescriptor<bool> recenable;
+		PropertyDescriptor<bool> select;
+		PropertyDescriptor<bool> edit;
+	}	
+}
+
+void
+RouteGroup::make_property_quarks ()
+{
+	Properties::relative.id = g_quark_from_static_string (X_("relative"));
+	Properties::active.id = g_quark_from_static_string (X_("active"));
+	Properties::hidden.id = g_quark_from_static_string (X_("hidden"));
+	Properties::gain.id = g_quark_from_static_string (X_("gain"));
+	Properties::mute.id = g_quark_from_static_string (X_("mute"));
+	Properties::solo.id = g_quark_from_static_string (X_("solo"));
+	Properties::recenable.id = g_quark_from_static_string (X_("recenable"));
+	Properties::select.id = g_quark_from_static_string (X_("select"));
+	Properties::edit.id = g_quark_from_static_string (X_("edit"));
+}
+
+#define ROUTE_GROUP_DEFAULT_PROPERTIES  _relative (Properties::relative, FlagsChange, false) \
+	, _active (Properties::active, FlagsChange, false) \
+	, _hidden (Properties::hidden, FlagsChange, false) \
+	, _gain (Properties::gain, PropertiesChange, false) \
+	, _mute (Properties::mute, PropertiesChange, false) \
+	, _solo (Properties::solo, PropertiesChange , false) \
+	, _recenable (Properties::recenable, PropertiesChange, false) \
+	, _select (Properties::select, PropertiesChange, false) \
+	, _edit (Properties::edit, PropertiesChange , false)
+
+RouteGroup::RouteGroup (Session& s, const string &n)
+	: SessionObject (s, n)
 	, routes (new RouteList)
-	, _name (n)
-	, _flags (f)
-	, _properties (Property (p))
+	, ROUTE_GROUP_DEFAULT_PROPERTIES
 {
+	_xml_node_name = X_("RegionGroup");
+
+	add_property (_relative);
+	add_property (_active);
+	add_property (_hidden);
+	add_property (_gain);
+	add_property (_mute);
+	add_property (_solo);
+	add_property (_recenable);
+	add_property (_select);
+	add_property (_edit);
 }
 
 RouteGroup::~RouteGroup ()
@@ -60,14 +110,6 @@ RouteGroup::~RouteGroup ()
 	}
 }
 
-void
-RouteGroup::set_name (string str)
-{
-	_name = str;
-	_session.set_dirty ();
-	FlagsChanged (0); /* EMIT SIGNAL */
-}
-
 /** Add a route to a group.  Adding a route which is already in the group is allowed; nothing will happen.
  *  @param r Route to add.
  */
@@ -163,9 +205,8 @@ XMLNode&
 RouteGroup::get_state (void)
 {
 	XMLNode *node = new XMLNode ("RouteGroup");
-	node->add_property ("name", _name);
-	node->add_property ("flags", enum_2_string (_flags));
-	node->add_property ("properties", enum_2_string (_properties));
+	
+	add_properties (*node);
 
 	if (!routes->empty()) {
 		stringstream str;
@@ -189,18 +230,6 @@ RouteGroup::set_state (const XMLNode& node, int version)
 
 	const XMLProperty *prop;
 
-	if ((prop = node.property ("name")) != 0) {
-		_name = prop->value();
-	}
-
-	if ((prop = node.property ("flags")) != 0) {
-		_flags = Flag (string_2_enum (prop->value(), _flags));
-	}
-
-	if ((prop = node.property ("properties")) != 0) {
-		_properties = Property (string_2_enum (prop->value(), _properties));
-	}
-
 	if ((prop = node.property ("routes")) != 0) {
 		stringstream str (prop->value());
 		vector<string> ids;
@@ -222,23 +251,77 @@ RouteGroup::set_state (const XMLNode& node, int version)
 int
 RouteGroup::set_state_2X (const XMLNode& node, int /*version*/)
 {
-	XMLProperty const * prop;
+	set_properties (node);
 
-	if ((prop = node.property ("name")) != 0) {
-		_name = prop->value();
+	if (node.name() == "MixGroup") {
+		_gain = true;
+		_mute = true;
+		_solo = true;
+		_recenable = true;
+		_edit = false;
+	} else if (node.name() == "EditGroup") {
+		_gain = false;
+		_mute = false;
+		_solo = false;
+		_recenable = false;
+		_edit = true;
 	}
 
-	if ((prop = node.property ("flags")) != 0) {
-		_flags = Flag (string_2_enum (prop->value(), _flags));
+	return 0;
+}
+
+void
+RouteGroup::set_gain (bool yn)
+{
+	if (is_gain() == yn) {
+		return;
 	}
+	_gain = yn;
+}
 
-	if (node.name() == "MixGroup") {
-		_properties = Property (Gain | Mute | Solo | RecEnable);
-	} else if (node.name() == "EditGroup") {
-		_properties = Property (Select | Edit);
+void
+RouteGroup::set_mute (bool yn)
+{
+	if (is_mute() == yn) {
+		return;
 	}
+	_mute = yn;
+}
 
-	return 0;
+void
+RouteGroup::set_solo (bool yn)
+{
+	if (is_solo() == yn) {
+		return;
+	}
+	_solo = yn;
+}
+
+void
+RouteGroup::set_recenable (bool yn)
+{
+	if (is_recenable() == yn) {
+		return;
+	}
+	_recenable = yn;
+}
+
+void
+RouteGroup::set_select (bool yn)
+{
+	if (is_select() == yn) {
+		return;
+	}
+	_select = yn;
+}
+
+void
+RouteGroup::set_edit (bool yn)
+{
+	if (is_edit() == yn) {
+		return;
+	}
+	_edit = yn;
 }
 
 void
@@ -247,11 +330,7 @@ RouteGroup::set_active (bool yn, void *src)
 	if (is_active() == yn) {
 		return;
 	}
-	if (yn) {
-		_flags = Flag (_flags | Active);
-	} else {
-		_flags = Flag (_flags & ~Active);
-	}
+	_active = yn;
 	_session.set_dirty ();
 	FlagsChanged (src); /* EMIT SIGNAL */
 }
@@ -263,31 +342,26 @@ RouteGroup::set_relative (bool yn, void *src)
 	if (is_relative() == yn) {
 		return;
 	}
-	if (yn) {
-		_flags = Flag (_flags | Relative);
-	} else {
-		_flags = Flag (_flags & ~Relative);
-	}
+	_relative = yn;
 	_session.set_dirty ();
 	FlagsChanged (src); /* EMIT SIGNAL */
 }
 
 void
 RouteGroup::set_hidden (bool yn, void *src)
-
 {
 	if (is_hidden() == yn) {
 		return;
 	}
 	if (yn) {
-		_flags = Flag (_flags | Hidden);
+		_hidden = true;
 		if (Config->get_hiding_groups_deactivates_groups()) {
-			_flags = Flag (_flags & ~Active);
+			_active = false;
 		}
 	} else {
-		_flags = Flag (_flags & ~Hidden);
+		_hidden = false;
 		if (Config->get_hiding_groups_deactivates_groups()) {
-			_flags = Flag (_flags | Active);
+			_active = true;
 		}
 	}
 	_session.set_dirty ();
@@ -357,3 +431,29 @@ RouteGroup::destroy_subgroup ()
 	_session.remove_route (subgroup_bus);
 	subgroup_bus.reset ();
 }
+
+bool
+RouteGroup::enabled_property (PBD::PropertyID prop)
+{
+	if (Properties::relative.id == prop) {
+		return is_relative();
+	} else if (Properties::active.id == prop) {
+		return is_active();
+	} else if (Properties::hidden.id == prop) {
+		return is_hidden();
+	} else if (Properties::gain.id == prop) {
+		return is_gain();
+	} else if (Properties::mute.id == prop) {
+		return is_mute();
+	} else if (Properties::solo.id == prop) {
+		return is_solo();
+	} else if (Properties::recenable.id == prop) {
+		return is_recenable();
+	} else if (Properties::select.id == prop) {
+		return is_select();
+	} else if (Properties::edit.id == prop) {
+		return is_edit();
+	}
+
+	return false;
+}
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 8034f74033..e5b57115c1 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -2840,7 +2840,7 @@ Session::update_region_name_map (boost::shared_ptr<Region> region)
 }
 
 void
-Session::region_changed (Change what_changed, boost::weak_ptr<Region> weak_region)
+Session::region_changed (PropertyChange what_changed, boost::weak_ptr<Region> weak_region)
 {
 	boost::shared_ptr<Region> region (weak_region.lock ());
 
@@ -3675,7 +3675,7 @@ Session::bundle_by_name (string name) const
 }
 
 void
-Session::tempo_map_changed (Change)
+Session::tempo_map_changed (PropertyChange)
 {
 	clear_clicks ();
 
@@ -4069,9 +4069,14 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
 
 		/* construct a region to represent the bounced material */
 
-		result = RegionFactory::create (srcs, 0,
-				srcs.front()->length(srcs.front()->timeline_position()),
-				region_name_from_path (srcs.front()->name(), true));
+		PropertyList plist;
+		
+		plist.add (Properties::start, 0);
+		plist.add (Properties::length, srcs.front()->length(srcs.front()->timeline_position()));
+		plist.add (Properties::name, region_name_from_path (srcs.front()->name(), true));
+		
+		result = RegionFactory::create (srcs, plist);
+			   
 	}
 
   out:
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 93cf6b3791..face9388bc 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -92,7 +92,6 @@
 #include "ardour/midi_track.h"
 #include "ardour/named_selection.h"
 #include "ardour/processor.h"
-#include "ardour/region_command.h"
 #include "ardour/region_factory.h"
 #include "ardour/route_group.h"
 #include "ardour/send.h"
@@ -2946,16 +2945,6 @@ Session::restore_history (string snapshot_name)
 					error << _("Failed to downcast MidiSource for DeltaCommand") << endmsg;
 				}
 
-			} else if (n->name() == "RegionCommand") {
-				PBD::ID id (n->property ("region")->value());
-				boost::shared_ptr<Region> region = RegionFactory::region_by_id (id);
-
-				if (region) {
-					ut->add_command (new RegionCommand (region, *n));
-				} else {
-					error << string_compose (_("Region command references an unknown region ID=%1"), id.to_s()) << endmsg;
-				}
-
 			} else if (n->name() == "StatefulDiffCommand") {
 				if ((c = stateful_diff_command_factory (n))) {
 					ut->add_command (c);
diff --git a/libs/ardour/sndfilesource.cc b/libs/ardour/sndfilesource.cc
index de8ce330e1..05de692016 100644
--- a/libs/ardour/sndfilesource.cc
+++ b/libs/ardour/sndfilesource.cc
@@ -48,7 +48,7 @@ using Glib::ustring;
 
 gain_t* SndFileSource::out_coefficient = 0;
 gain_t* SndFileSource::in_coefficient = 0;
-nframes_t SndFileSource::xfade_frames = 64;
+framecnt_t SndFileSource::xfade_frames = 64;
 const Source::Flag SndFileSource::default_writable_flags = Source::Flag (
 		Source::Writable |
 		Source::Removable |
@@ -269,13 +269,13 @@ SndFileSource::sample_rate () const
 	return _info.samplerate;
 }
 
-nframes_t
-SndFileSource::read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const
+framecnt_t
+SndFileSource::read_unlocked (Sample *dst, framepos_t start, framecnt_t cnt) const
 {
 	int32_t nread;
 	float *ptr;
 	uint32_t real_cnt;
-	nframes_t file_cnt;
+	framepos_t file_cnt;
 
 	if (start > _length) {
 
@@ -297,7 +297,7 @@ SndFileSource::read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const
 	}
 
 	if (file_cnt != cnt) {
-		nframes_t delta = cnt - file_cnt;
+		framepos_t delta = cnt - file_cnt;
 		memset (dst+file_cnt, 0, sizeof (Sample) * delta);
 	}
 
@@ -342,8 +342,8 @@ SndFileSource::read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const
 	return nread;
 }
 
-nframes_t
-SndFileSource::write_unlocked (Sample *data, nframes_t cnt)
+framecnt_t
+SndFileSource::write_unlocked (Sample *data, framecnt_t cnt)
 {
 	if (destructive()) {
 		return destructive_write_unlocked (data, cnt);
@@ -352,8 +352,8 @@ SndFileSource::write_unlocked (Sample *data, nframes_t cnt)
 	}
 }
 
-nframes_t
-SndFileSource::nondestructive_write_unlocked (Sample *data, nframes_t cnt)
+framecnt_t
+SndFileSource::nondestructive_write_unlocked (Sample *data, framecnt_t cnt)
 {
 	if (!writable()) {
 		warning << string_compose (_("attempt to write a non-writable audio file source (%1)"), _path) << endmsg;
@@ -366,7 +366,7 @@ SndFileSource::nondestructive_write_unlocked (Sample *data, nframes_t cnt)
 		return 0;
 	}
 
-	nframes_t oldlen;
+	framecnt_t oldlen;
 	int32_t frame_pos = _length;
 
 	if (write_float (data, frame_pos, cnt) != cnt) {
@@ -385,10 +385,10 @@ SndFileSource::nondestructive_write_unlocked (Sample *data, nframes_t cnt)
 	return cnt;
 }
 
-nframes_t
-SndFileSource::destructive_write_unlocked (Sample* data, nframes_t cnt)
+framecnt_t
+SndFileSource::destructive_write_unlocked (Sample* data, framecnt_t cnt)
 {
-	nframes_t old_file_pos;
+	framepos_t old_file_pos;
 
 	if (!writable()) {
 		warning << string_compose (_("attempt to write a non-writable audio file source (%1)"), _path) << endmsg;
@@ -551,8 +551,8 @@ SndFileSource::set_header_timeline_position ()
 	}
 }
 
-nframes_t
-SndFileSource::write_float (Sample* data, sframes_t frame_pos, nframes_t cnt)
+framecnt_t
+SndFileSource::write_float (Sample* data, framepos_t frame_pos, framecnt_t cnt)
 {
 	if (sf_seek (sf, frame_pos, SEEK_SET|SFM_WRITE) < 0) {
 		char errbuf[256];
@@ -568,7 +568,7 @@ SndFileSource::write_float (Sample* data, sframes_t frame_pos, nframes_t cnt)
 	return cnt;
 }
 
-sframes_t
+framepos_t
 SndFileSource::natural_position() const
 {
 	return _timeline_position;
@@ -621,15 +621,15 @@ SndFileSource::mark_capture_end()
 	}
 }
 
-nframes_t
-SndFileSource::crossfade (Sample* data, nframes_t cnt, int fade_in)
+framecnt_t
+SndFileSource::crossfade (Sample* data, framecnt_t cnt, int fade_in)
 {
-	nframes_t xfade = min (xfade_frames, cnt);
-	nframes_t nofade = cnt - xfade;
+	framecnt_t xfade = min (xfade_frames, cnt);
+	framecnt_t nofade = cnt - xfade;
 	Sample* fade_data = 0;
-	nframes_t fade_position = 0; // in frames
+	framepos_t fade_position = 0; // in frames
 	ssize_t retval;
-	nframes_t file_cnt;
+	framecnt_t file_cnt;
 
 	if (fade_in) {
 		fade_position = file_pos;
@@ -673,7 +673,7 @@ SndFileSource::crossfade (Sample* data, nframes_t cnt, int fade_in)
 	}
 
 	if (file_cnt != xfade) {
-		nframes_t delta = xfade - file_cnt;
+		framecnt_t delta = xfade - file_cnt;
 		memset (xfade_buf+file_cnt, 0, sizeof (Sample) * delta);
 	}
 
@@ -686,7 +686,7 @@ SndFileSource::crossfade (Sample* data, nframes_t cnt, int fade_in)
 
 	if (xfade == xfade_frames) {
 
-		nframes_t n;
+		framecnt_t n;
 
 		/* use the standard xfade curve */
 
@@ -717,10 +717,10 @@ SndFileSource::crossfade (Sample* data, nframes_t cnt, int fade_in)
 
 		compute_equal_power_fades (xfade, in, out);
 
-		for (nframes_t n = 0; n < xfade; ++n) {
+		for (framecnt_t n = 0; n < xfade; ++n) {
 			xfade_buf[n] = (xfade_buf[n] * out[n]) + (fade_data[n] * in[n]);
 		}
-
+		
 	} else if (xfade) {
 
 		/* long xfade length, has to be computed across several calls */
@@ -775,7 +775,7 @@ SndFileSource::setup_standard_crossfades (Session const & s, nframes_t rate)
 	   before any DFS's are created.
 	*/
 
-	xfade_frames = (nframes_t) floor ((s.config.get_destructive_xfade_msecs () / 1000.0) * rate);
+	xfade_frames = (framecnt_t) floor ((s.config.get_destructive_xfade_msecs () / 1000.0) * rate);
 
 	delete [] out_coefficient;
 	delete [] in_coefficient;
diff --git a/libs/ardour/strip_silence.cc b/libs/ardour/strip_silence.cc
index 256e06eccf..0f58ccf9a3 100644
--- a/libs/ardour/strip_silence.cc
+++ b/libs/ardour/strip_silence.cc
@@ -52,7 +52,7 @@ StripSilence::run (boost::shared_ptr<Region> r)
 	}
 
 	/* find periods of silence in the region */
-	std::list<std::pair<nframes_t, nframes_t> > const silence =
+	std::list<std::pair<frameoffset_t, framecnt_t> > const silence =
 		region->find_silence (dB_to_coefficient (_threshold), _minimum_length);
 
 	if (silence.size () == 1 && silence.front().first == 0 && silence.front().second == region->length() - 1) {
@@ -66,10 +66,10 @@ StripSilence::run (boost::shared_ptr<Region> r)
 		return 0;
 	}
 
-	std::list<std::pair<nframes_t, nframes_t > >::const_iterator s = silence.begin ();
-	nframes_t const pos = region->position ();
-	nframes_t const end = region->start () + region->length() - 1;
-	nframes_t const start = region->start ();
+	std::list<std::pair<framepos_t, framecnt_t > >::const_iterator s = silence.begin ();
+	framepos_t const pos = region->position ();
+	framepos_t const end = region->start () + region->length() - 1;
+	framepos_t const start = region->start ();
 
 	region = boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (region));
 	region->set_name (session.new_region_name (region->name ()));
diff --git a/libs/ardour/tempo.cc b/libs/ardour/tempo.cc
index 9dcce637e6..be34b79ccc 100644
--- a/libs/ardour/tempo.cc
+++ b/libs/ardour/tempo.cc
@@ -299,7 +299,7 @@ void
 TempoMap::move_tempo (TempoSection& tempo, const BBT_Time& when)
 {
 	if (move_metric_section (tempo, when) == 0) {
-		StateChanged (Change (0));
+		StateChanged (PropertyChange (0));
 	}
 }
 
@@ -307,7 +307,7 @@ void
 TempoMap::move_meter (MeterSection& meter, const BBT_Time& when)
 {
 	if (move_metric_section (meter, when) == 0) {
-		StateChanged (Change (0));
+		StateChanged (PropertyChange (0));
 	}
 }
 
@@ -334,7 +334,7 @@ TempoMap::remove_tempo (const TempoSection& tempo)
 	}
 
 	if (removed) {
-		StateChanged (Change (0));
+		StateChanged (PropertyChange (0));
 	}
 }
 
@@ -361,7 +361,7 @@ TempoMap::remove_meter (const MeterSection& tempo)
 	}
 
 	if (removed) {
-		StateChanged (Change (0));
+		StateChanged (PropertyChange (0));
 	}
 }
 
@@ -406,7 +406,7 @@ TempoMap::add_tempo (const Tempo& tempo, BBT_Time where)
 		do_insert (new TempoSection (where, tempo.beats_per_minute(), tempo.note_type()), true);
 	}
 
-	StateChanged (Change (0));
+	StateChanged (PropertyChange (0));
 }
 
 void
@@ -417,7 +417,7 @@ TempoMap::add_tempo (const Tempo& tempo, nframes64_t where)
 		do_insert (new TempoSection (where, tempo.beats_per_minute(), tempo.note_type()), false);
 	}
 
-	StateChanged (Change (0));
+	StateChanged (PropertyChange (0));
 }
 
 void
@@ -445,7 +445,7 @@ TempoMap::replace_tempo (TempoSection& existing, const Tempo& replacement)
 	}
 
 	if (replaced) {
-		StateChanged (Change (0));
+		StateChanged (PropertyChange (0));
 	}
 }
 
@@ -474,7 +474,7 @@ TempoMap::add_meter (const Meter& meter, BBT_Time where)
 		do_insert (new MeterSection (where, meter.beats_per_bar(), meter.note_divisor()), true);
 	}
 
-	StateChanged (Change (0));
+	StateChanged (PropertyChange (0));
 }
 
 void
@@ -485,7 +485,7 @@ TempoMap::add_meter (const Meter& meter, nframes64_t where)
 		do_insert (new MeterSection (where, meter.beats_per_bar(), meter.note_divisor()), false);
 	}
 
-	StateChanged (Change (0));
+	StateChanged (PropertyChange (0));
 }
 
 void
@@ -511,7 +511,7 @@ TempoMap::replace_meter (MeterSection& existing, const Meter& replacement)
 	}
 
 	if (replaced) {
-		StateChanged (Change (0));
+		StateChanged (PropertyChange (0));
 	}
 }
 
@@ -524,7 +524,7 @@ TempoMap::change_initial_tempo (double beats_per_minute, double note_type)
 	for (Metrics::iterator i = metrics->begin(); i != metrics->end(); ++i) {
 		if ((t = dynamic_cast<TempoSection*> (*i)) != 0) {
 			*((Tempo*) t) = newtempo;
-			StateChanged (Change (0));
+			StateChanged (PropertyChange (0));
 			break;
 		}
 	}
@@ -570,7 +570,7 @@ TempoMap::change_existing_tempo_at (nframes64_t where, double beats_per_minute,
 	/* reset */
 
 	*((Tempo*)prev) = newtempo;
-	StateChanged (Change (0));
+	StateChanged (PropertyChange (0));
 }
 
 const MeterSection&
@@ -1609,7 +1609,7 @@ TempoMap::set_state (const XMLNode& node, int /*version*/)
 		}
 	}
 
-	StateChanged (Change (0));
+	StateChanged (PropertyChange (0));
 
 	return 0;
 }
@@ -1673,7 +1673,7 @@ TempoMap::insert_time (nframes64_t where, nframes64_t amount)
 
 	timestamp_metrics (false);
 
-	StateChanged (Change (0));
+	StateChanged (PropertyChange (0));
 }
 
 BBT_Time
diff --git a/libs/ardour/track.cc b/libs/ardour/track.cc
index 1aa917ca9d..8ad3650343 100644
--- a/libs/ardour/track.cc
+++ b/libs/ardour/track.cc
@@ -171,7 +171,7 @@ Track::set_record_enable (bool yn, void *src)
 		return;
 	}
 
-	if (_route_group && src != _route_group && _route_group->active_property (RouteGroup::RecEnable)) {
+	if (_route_group && src != _route_group && _route_group->is_active() && _route_group->is_recenable()) {
 		_route_group->apply (&Track::set_record_enable, yn, _route_group);
 		return;
 	}
diff --git a/libs/ardour/wscript b/libs/ardour/wscript
index ee9aa14850..bd3ceeb668 100644
--- a/libs/ardour/wscript
+++ b/libs/ardour/wscript
@@ -143,10 +143,9 @@ libardour_sources = [
 	'quantize.cc',
 	'rc_configuration.cc',
 	'recent_sessions.cc',
-	'region.cc',
-	'region_command.cc',
 	'region_factory.cc',
 	'resampled_source.cc',
+	'region.cc',
 	'return.cc',
 	'reverse.cc',
 	'route.cc',
@@ -165,6 +164,7 @@ libardour_sources = [
 	'session_handle.cc',
 	'session_metadata.cc',
 	'session_midi.cc',
+	'session_object.cc',
 	'session_playlists.cc',
 	'session_process.cc',
 	'session_rtevents.cc',
diff --git a/libs/evoral/evoral/midi_events.h b/libs/evoral/evoral/midi_events.h
index a235d9a3fc..3a56eeb9b2 100644
--- a/libs/evoral/evoral/midi_events.h
+++ b/libs/evoral/evoral/midi_events.h
@@ -107,8 +107,8 @@
 #define MIDI_CMD_NOTE_OFF               0x80 /**< Note Off */
 #define MIDI_CMD_NOTE_ON                0x90 /**< Note On */
 #define MIDI_CMD_NOTE_PRESSURE          0xA0 /**< Key Pressure */
-#define MIDI_CMD_CONTROL                0xB0 /**< Control Change */
-#define MIDI_CMD_PGM_CHANGE             0xC0 /**< Program Change */
+#define MIDI_CMD_CONTROL                0xB0 /**< Control PropertyChange */
+#define MIDI_CMD_PGM_CHANGE             0xC0 /**< Program PropertyChange */
 #define MIDI_CMD_CHANNEL_PRESSURE       0xD0 /**< Channel Pressure */
 #define MIDI_CMD_BENDER                 0xE0 /**< Pitch Bender */
 #define MIDI_CMD_COMMON_SYSEX           0xF0 /**< Sysex (System Exclusive) Begin */
diff --git a/libs/evoral/src/libsmf/smf.h b/libs/evoral/src/libsmf/smf.h
index 8311254841..212105c5d0 100644
--- a/libs/evoral/src/libsmf/smf.h
+++ b/libs/evoral/src/libsmf/smf.h
@@ -186,11 +186,11 @@
  * adding the event (using smf_track_add_event_seconds(), smf_track_add_event_pulses() or
  * smf_track_add_event_delta_pulses()); the remaining two values are computed from that.
  *
- * Tempo related stuff happens automatically - when you add a metaevent that is Tempo Change or
- * Time Signature, libsmf adds that event to the tempo map.  If you remove Tempo Change event
+ * Tempo related stuff happens automatically - when you add a metaevent that is Tempo PropertyChange or
+ * Time Signature, libsmf adds that event to the tempo map.  If you remove Tempo PropertyChange event
  * that is in the middle of the song, the rest of the events will have their event->time_seconds
  * recomputed from event->time_pulses before smf_event_remove_from_track() function returns.
- * Adding Tempo Change in the middle of the song works in a similar way.
+ * Adding Tempo PropertyChange in the middle of the song works in a similar way.
  *
  * MIDI data (event->midi_buffer) is always kept in normalized form - it always begins with
  * status byte (no running status), there are no System Realtime events embedded in them etc.
diff --git a/libs/midi++2/midi++/names.h b/libs/midi++2/midi++/names.h
index e4fdd241db..a74e74c1cf 100644
--- a/libs/midi++2/midi++/names.h
+++ b/libs/midi++2/midi++/names.h
@@ -40,9 +40,9 @@ inline static const char* midi_name(uint8_t status)
 	case MIDI_CMD_NOTE_PRESSURE:
 		return "Key Pressure"; break;
 	case MIDI_CMD_CONTROL:
-		return "Control Change"; break;
+		return "Control PropertyChange"; break;
 	case MIDI_CMD_PGM_CHANGE:
-		return "Program Change"; break;
+		return "Program PropertyChange"; break;
 	case MIDI_CMD_CHANNEL_PRESSURE:
 		return "Channel Pressure"; break;
 	case MIDI_CMD_BENDER:
diff --git a/libs/midi++2/parser.cc b/libs/midi++2/parser.cc
index 52de52c2d2..a42a465193 100644
--- a/libs/midi++2/parser.cc
+++ b/libs/midi++2/parser.cc
@@ -196,7 +196,7 @@ Parser::trace_event (Parser &, byte *msg, size_t len)
 		*o << trace_prefix 
 		   << "Channel "
 		   << (msg[0]&0xF)+1
-		   <<  " Program Change ProgNum "
+		   <<  " Program PropertyChange ProgNum "
 		   << (int) msg[1]
 		   << endmsg;
 		break;
diff --git a/libs/pbd/pbd/properties.h b/libs/pbd/pbd/properties.h
index 5bab97229c..10c661102d 100644
--- a/libs/pbd/pbd/properties.h
+++ b/libs/pbd/pbd/properties.h
@@ -21,26 +21,35 @@
 #define __pbd_properties_h__
 
 #include <string>
+#include <sstream>
 #include <list>
-#include <glib/glib.h>
+#include <glib.h>
 
-class XMLNode;
+#include "pbd/xml++.h"
 
 namespace PBD {
 
 enum PropertyChange {
-	range_guarantee = ~0
+	range_guarantee = ~0ULL
 };
 
 PropertyChange new_change ();
 
+typedef GQuark PropertyID;
+
+template<typename T> 
+struct PropertyDescriptor {
+    PropertyID id;
+    typedef T value_type;
+};
+
 /** Base (non template) part of Property */	
 class PropertyBase
 {
 public:
-	PropertyBase (GQuark quark, PropertyChange c)
+	PropertyBase (PropertyID pid, PropertyChange c)
 		: _have_old (false)
-		, _property_quark (q)
+		, _property_id (pid)
 		, _change (c)
 	{
 
@@ -52,19 +61,21 @@ public:
 	}
 
 	virtual void diff (XMLNode *, XMLNode *) const = 0;
+	virtual void diff (PropertyChange&) const = 0;
 	virtual PropertyChange set_state (XMLNode const &) = 0;
 	virtual void add_state (XMLNode &) const = 0;
 
-	std::string property_name() const { return g_quark_to_string (_property_quark); }
+	const gchar* property_name() const { return g_quark_to_string (_property_id); }
 	PropertyChange change() const { return _change; }
+	PropertyID id() const { return _property_id; }
 
-	bool operator== (GQuark q) const {
-		return _property_quark == q;
+	bool operator== (PropertyID pid) const {
+		return _property_id == pid;
 	}
 
 protected:
 	bool _have_old;
-	GQuark _property_quark;
+	PropertyID _property_id;
 	PropertyChange _change;
 };
 
@@ -73,17 +84,16 @@ template <class T>
 class PropertyTemplate : public PropertyBase
 {
 public:
-	PropertyTemplate (GQuark q, PropertyChange c, T const & v)
-		: PropertyBase (q, c)
+	PropertyTemplate (PropertyDescriptor<T> p, PropertyChange c, T const & v)
+		: PropertyBase (p.id, c)
 		, _current (v)
 	{
 
 	}
-
 	PropertyTemplate<T> & operator= (PropertyTemplate<T> const & s) {
 		/* XXX: isn't there a nicer place to do this? */
 		_have_old = s._have_old;
-		_property_quark = s._property_quark;
+		_property_id = s._property_id;
 		_change = s._change;
 		
 		_current = s._current;
@@ -119,8 +129,14 @@ public:
 
 	void diff (XMLNode* old, XMLNode* current) const {
 		if (_have_old) {
-			old->add_property (g_quark_to_string (_property_quark), to_string (_old));
-			current->add_property (g_quark_to_string (_property_quark), to_string (_current));
+			old->add_property (g_quark_to_string (_property_id), to_string (_old));
+			current->add_property (g_quark_to_string (_property_id), to_string (_current));
+		}
+	}
+	
+	void diff (PropertyChange& c) const {
+		if (_have_old && _change) {
+			c = PropertyChange (c | _change);
 		}
 	}
 
@@ -129,24 +145,23 @@ public:
 	 *  @return PropertyChange effected, or 0.
 	 */
 	PropertyChange set_state (XMLNode const & node) {
-		XMLProperty const * p = node.property (g_quark_to_string (_property_quark));
+		XMLProperty const * p = node.property (g_quark_to_string (_property_id));
+		PropertyChange c = PropertyChange (0);
 
 		if (p) {
 			T const v = from_string (p->value ());
 
-			if (v == _current) {
-				return PropertyChange (0);
+			if (v != _current) {
+				set (v);
+				c = _change;
 			}
-
-			set (v);
-			return _change;
 		}
 
-		return PropertyChange (0);
+		return c;
 	}
 
 	void add_state (XMLNode & node) const {
-		node.add_property (g_quark_to_string (_property_quark), to_string (_current));
+		node.add_property (g_quark_to_string (_property_id), to_string (_current));
 	}
 
 protected:
@@ -176,11 +191,17 @@ template <class T>
 class Property : public PropertyTemplate<T>
 {
 public:
-	Property (GQuark q, PropertyChange c, T const & v)
+	Property (PropertyDescriptor<T> q, PropertyChange c, T const & v)
 		: PropertyTemplate<T> (q, c, v)
 	{
 
 	}
+
+	Property (PropertyDescriptor<T> q, T const & v)
+		: PropertyTemplate<T> (q, PropertyChange (0), v)
+	{
+
+	}
 	
 	T & operator= (T const & v) {
 		this->set (v);
@@ -188,8 +209,14 @@ public:
 	}
 	
 private:	
-	std::string to_string (T const & v) const {
-		// XXX LocaleGuard
+        /* note that we do not set a locale for the streams used
+	   in to_string() or from_string(), because we want the
+	   format to be portable across locales (i.e. C or
+	   POSIX). Also, there is the small matter of
+	   std::locale aborting on OS X if used with anything
+	   other than C or POSIX locales.
+	*/
+        std::string to_string (T const & v) const {
 		std::stringstream s;
 		s.precision (12); // in case its floating point
 		s << v;
@@ -197,15 +224,53 @@ private:
 	}
 
 	T from_string (std::string const & s) const {
-		// XXX LocaleGuard	
 		std::stringstream t (s);
 		T v;
-		t.precision (12); // in case its floating point
 		t >> v;
 		return v;
 	}
 };
 
+class PropertyList : public std::map<PropertyID,PropertyBase*>
+{
+public:
+    PropertyList() : property_owner (true) {}
+    virtual ~PropertyList() {
+	    if (property_owner)
+		    for (std::map<PropertyID,PropertyBase*>::iterator i = begin(); i != end(); ++i) {
+			    delete i->second;
+		    }
+    }
+    /* classes that own property lists use this to add their
+       property members to their plists.
+    */
+    bool add (PropertyBase& p) {
+	    return insert (value_type (p.id(), &p)).second;
+    }
+
+    /* code that is constructing a property list for use 
+       in setting the state of an object uses this.
+    */
+    template<typename T, typename V> bool add (PropertyDescriptor<T> pid, const V& v) {
+	    return insert (value_type (pid.id, new Property<T> (pid, (T) v))).second;
+    }
+
+protected:
+    bool property_owner;
+};
+
+/** A variant of PropertyList that does not delete its
+    property list in its destructor. Objects with their
+    own Properties store them in an OwnedPropertyList
+    to avoid having them deleted at the wrong time.
+*/
+
+class OwnedPropertyList : public PropertyList
+{
+public:
+    OwnedPropertyList() { property_owner = false; }
+};
+	    
 } /* namespace PBD */
 
 #endif /* __pbd_properties_h__ */
diff --git a/libs/pbd/pbd/stateful.h b/libs/pbd/pbd/stateful.h
index 02224bb5e1..9ef1a9ef73 100644
--- a/libs/pbd/pbd/stateful.h
+++ b/libs/pbd/pbd/stateful.h
@@ -21,10 +21,12 @@
 #define __pbd_stateful_h__
 
 #include <string>
+#include <list>
 #include <cassert>
 #include "pbd/id.h"
 #include "pbd/xml++.h"
 #include "pbd/enumwriter.h"
+#include "pbd/properties.h"
 
 class XMLNode;
 
@@ -34,201 +36,6 @@ namespace sys {
 	class path;
 }
 
-enum Change {
-	range_guarantee = ~0
-};
-
-Change new_change ();
-
-/** Base (non template) part of State */	
-class StateBase
-{
-public:
-	StateBase (std::string const & p, Change c)
-		: _have_old (false)
-		, _xml_property_name (p)
-		, _change (c)
-	{
-
-	}
-
-	/** Forget about any old value for this state */
-	void clear_history () {
-		_have_old = false;
-	}
-
-	virtual void diff (XMLNode *, XMLNode *) const = 0;
-	virtual Change set_state (XMLNode const &) = 0;
-	virtual void add_state (XMLNode &) const = 0;
-
-protected:
-	bool _have_old;
-	std::string _xml_property_name;
-	Change _change;
-};
-
-/** Parent class for classes which represent a single piece of state in a Stateful object */
-template <class T>
-class StateTemplate : public StateBase
-{
-public:
-	StateTemplate (std::string const & p, Change c, T const & v)
-		: StateBase (p, c)
-		, _current (v)
-	{
-
-	}
-
-	StateTemplate<T> & operator= (StateTemplate<T> const & s) {
-		/* XXX: isn't there a nicer place to do this? */
-		_have_old = s._have_old;
-		_xml_property_name = s._xml_property_name;
-		_change = s._change;
-		
-		_current = s._current;
-		_old = s._old;
-		return *this;
-	}
-
-	T & operator= (T const & v) {
-		set (v);
-		return _current;
-	}
-
-	T & operator+= (T const & v) {
-		set (_current + v);
-		return _current;
-	}
-	
-	bool operator== (const T& other) const {
-		return _current == other;
-	}
-
-	bool operator!= (const T& other) const {
-		return _current != other;
-	}
-
-	operator T const & () const {
-		return _current;
-	}
-
-	T const & val () const {
-		return _current;
-	}
-
-	void diff (XMLNode* old, XMLNode* current) const {
-		if (_have_old) {
-			old->add_property (_xml_property_name.c_str(), to_string (_old));
-			current->add_property (_xml_property_name.c_str(), to_string (_current));
-		}
-	}
-
-	/** Try to set state from the property of an XML node.
-	 *  @param node XML node.
-	 *  @return Change effected, or 0.
-	 */
-	Change set_state (XMLNode const & node) {
-		XMLProperty const * p = node.property (_xml_property_name.c_str());
-
-		if (p) {
-			T const v = from_string (p->value ());
-
-			if (v == _current) {
-				return Change (0);
-			}
-
-			set (v);
-			return _change;
-		}
-
-		return Change (0);
-	}
-
-	void add_state (XMLNode & node) const {
-		node.add_property (_xml_property_name.c_str(), to_string (_current));
-	}
-
-protected:
-	void set (T const & v) {
-		_old = _current;
-		_have_old = true;
-		_current = v;
-	}
-
-	virtual std::string to_string (T const & v) const = 0;
-	virtual T from_string (std::string const & s) const = 0;
-		
-	T _current;
-	T _old;
-};
-
-template<class T>	
-std::ostream& operator<< (std::ostream& os, StateTemplate<T> const & s)
-{
-	os << s.val();
-	return os;
-}
-
-/** Representation of a single piece of state in a Stateful; for use
- *  with types that can be written to / read from stringstreams.
- */
-template <class T>
-class State : public StateTemplate<T>
-{
-public:
-	State (std::string const & p, Change c, T const & v)
-		: StateTemplate<T> (p, c, v)
-	{
-
-	}
-	
-	T & operator= (T const & v) {
-		this->set (v);
-		return this->_current;
-	}
-	
-private:	
-	std::string to_string (T const & v) const {
-		std::stringstream s;
-		s.precision (12); // in case its floating point
-		s << v;
-		return s.str ();
-	}
-
-	T from_string (std::string const & s) const {
-		std::stringstream t (s);
-		T v;
-		t.precision (12); // in case its floating point
-		t >> v;
-		return v;
-	}
-};
-
-template <class T>
-class EnumState : public StateTemplate<T>
-{
-public:
-	EnumState (std::string const & p, Change c, T const & v)
-		: StateTemplate<T> (p, c, v)
-	{
-
-	}
-	
-	T & operator= (T const & v) {
-		this->set (v);
-		return this->_current;
-	}
-
-private:
-	std::string to_string (T const & v) const {
-		return enum_2_string (v);
-	}
-
-	T from_string (std::string const & v) const {
-		return T (string_2_enum (v, this->_current));
-	}
-};
-
 /** Base class for objects with saveable and undoable state */
 class Stateful {
   public:
@@ -236,14 +43,21 @@ class Stateful {
 	virtual ~Stateful();
 
 	virtual XMLNode& get_state (void) = 0;
-
 	virtual int set_state (const XMLNode&, int version) = 0;
+	/* derived types do not have to implement this, but probably should
+	   give it serious attention.
+	*/
+	virtual PropertyChange set_property (const PropertyBase&) { return PropertyChange (0); }
 
-	void add_state (StateBase & s) {
-		_states.push_back (&s);
+	PropertyChange set_properties (const PropertyList&);
+
+	void add_property (PropertyBase& s) {
+		_properties.add (s);
 	}
 
-	/* Extra XML nodes */
+	/* Extra XML node: so that 3rd parties can attach state to the XMLNode
+	   representing the state of this object.
+	 */
 
 	void add_extra_xml (XMLNode&);
 	XMLNode *extra_xml (const std::string& str);
@@ -251,7 +65,8 @@ class Stateful {
 	const PBD::ID& id() const { return _id; }
 
 	void clear_history ();
-	std::pair<XMLNode *, XMLNode*> diff ();
+	std::pair<XMLNode *, XMLNode*> diff () const;
+	void changed (PropertyChange&) const;
 
 	static int current_state_version;
 	static int loading_state_version;
@@ -260,15 +75,25 @@ class Stateful {
 
 	void add_instant_xml (XMLNode&, const sys::path& directory_path);
 	XMLNode *instant_xml (const std::string& str, const sys::path& directory_path);
-	Change set_state_using_states (XMLNode const &);
-	void add_states (XMLNode &);
+	void add_properties (XMLNode &);
+	/* derived types can call this from ::set_state() (or elsewhere)
+	   to get basic property setting done.
+	*/
+	PropertyChange set_properties (XMLNode const &);
+
+	
+	/* derived classes can implement this to do cross-checking
+	   of property values after either a PropertyList or XML 
+	   driven property change.
+	*/
+	virtual void post_set () { };
 
 	XMLNode *_extra_xml;
 	XMLNode *_instant_xml;
 	PBD::ID _id;
 
 	std::string _xml_node_name; ///< name of node to use for this object in XML
-	std::list<StateBase*> _states; ///< state variables that this object has
+	OwnedPropertyList _properties;
 };
 
 } // namespace PBD
diff --git a/libs/pbd/property.cc b/libs/pbd/property.cc
index 83bcf0fa2d..58e81c056b 100644
--- a/libs/pbd/property.cc
+++ b/libs/pbd/property.cc
@@ -17,6 +17,8 @@
 
 */
 
+#include <stdint.h>
+
 #include "pbd/properties.h"
 #include "pbd/error.h"
 
@@ -25,7 +27,7 @@
 using namespace PBD;
 
 PropertyChange
-new_change ()
+PBD::new_change ()
 {
 	static uint64_t change_bit = 1;
 
diff --git a/libs/pbd/stateful.cc b/libs/pbd/stateful.cc
index a50c54d7f5..a8dd7a4177 100644
--- a/libs/pbd/stateful.cc
+++ b/libs/pbd/stateful.cc
@@ -35,27 +35,6 @@ namespace PBD {
 int Stateful::current_state_version = 0;
 int Stateful::loading_state_version = 0;
 
-PBD::Change
-new_change ()
-{
-	Change c;
-	static uint32_t change_bit = 1;
-
-	/* catch out-of-range */
-	if (!change_bit)
-	{
-		fatal << _("programming error: ")
-			<< "change_bit out of range in ARDOUR::new_change()"
-			<< endmsg;
-		/*NOTREACHED*/
-	}
-
-	c = Change (change_bit);
-	change_bit <<= 1;	// if it shifts too far, change_bit == 0
-
-	return c;
-}
-
 Stateful::Stateful ()
 {
 	_extra_xml = 0;
@@ -174,8 +153,8 @@ Stateful::instant_xml (const string& str, const sys::path& directory_path)
 void
 Stateful::clear_history ()
 {
-	for (list<StateBase*>::iterator i = _states.begin(); i != _states.end(); ++i) {
-		(*i)->clear_history ();
+	for (OwnedPropertyList::iterator i = _properties.begin(); i != _properties.end(); ++i) {
+		i->second->clear_history ();
 	}
 }
 
@@ -185,42 +164,75 @@ Stateful::clear_history ()
  *  It is the caller's responsibility to delete the returned XMLNodes.
  */
 pair<XMLNode *, XMLNode *>
-Stateful::diff ()
+Stateful::diff () const
 {
 	XMLNode* old = new XMLNode (_xml_node_name);
 	XMLNode* current = new XMLNode (_xml_node_name);
 
-	for (list<StateBase*>::iterator i = _states.begin(); i != _states.end(); ++i) {
-		(*i)->diff (old, current);
+	for (OwnedPropertyList::const_iterator i = _properties.begin(); i != _properties.end(); ++i) {
+		i->second->diff (old, current);
 	}
 
 	return make_pair (old, current);
 }
+
+/** Modifies PropertyChange @param c to indicate what properties have changed since the last
+    time clear_history was called on this object. Note that not all properties have change
+    values - if this object has any such Property members, they will never show up in
+    the value of @param c. Note also that @param c is not cleared by this function.
+*/
+void
+Stateful::changed (PropertyChange& c) const
+{
+	for (OwnedPropertyList::const_iterator i = _properties.begin(); i != _properties.end(); ++i) {
+		i->second->diff (c);
+	}
+}	
 	
-/** Set state of _states from an XML node.
+/** Set state of some/all _properties from an XML node.
  *  @param node Node.
- *  @return Changes made.
+ *  @return PropertyChanges made.
  */
-Change
-Stateful::set_state_using_states (XMLNode const & node)
+PropertyChange
+Stateful::set_properties (XMLNode const & node)
 {
-	Change c = Change (0);
-	
-	for (list<StateBase*>::iterator i = _states.begin(); i != _states.end(); ++i) {
-		c = Change (c | (*i)->set_state (node));
+	PropertyChange c = PropertyChange (0);
+
+	for (OwnedPropertyList::iterator i = _properties.begin(); i != _properties.end(); ++i) {
+		c = PropertyChange (c | i->second->set_state (node));
+	}
+
+	post_set ();
+
+	return c;
+}
+
+PropertyChange
+Stateful::set_properties (const PropertyList& property_list)
+{
+	PropertyChange c = PropertyChange (0);
+	PropertyList::const_iterator p;
+
+	for (OwnedPropertyList::iterator i = _properties.begin(); i != _properties.end(); ++i) {
+		if ((p = property_list.find (i->first)) != property_list.end()) {
+			c = PropertyChange (c|set_property (*(p->second)));
+		}
 	}
+	
+	post_set ();
 
 	return c;
 }
 
-/** Add state of _states to an XML node.
+
+/** Add property states to an XML node.
  *  @param node Node.
  */
 void
-Stateful::add_states (XMLNode & node)
+Stateful::add_properties (XMLNode & node)
 {
-	for (list<StateBase*>::iterator i = _states.begin(); i != _states.end(); ++i) {
-		(*i)->add_state (node);
+	for (OwnedPropertyList::iterator i = _properties.begin(); i != _properties.end(); ++i) {
+		i->second->add_state (node);
 	}
 }
 
diff --git a/libs/pbd/wscript b/libs/pbd/wscript
index 8bd00bcff9..1c328e0410 100644
--- a/libs/pbd/wscript
+++ b/libs/pbd/wscript
@@ -74,6 +74,7 @@ def build(bld):
 		mountpoint.cc
 		pathscanner.cc
 		pool.cc
+                property.cc
 		pthread_utils.cc
 		receiver.cc
 		search_path.cc
diff --git a/vst/ardevst b/vst/ardevst
index c5f4242023..f254f908c7 100755
--- a/vst/ardevst
+++ b/vst/ardevst
@@ -1,6 +1,5 @@
 #!/bin/sh      
 
-. ../gtk2_ardour/ardev_common.sh
-
+. `dirname "$0"`/../build/default/gtk2_ardour/ardev_common_waf.sh
 export LD_LIBRARY_PATH=$TOP/gtk2_ardour:$LD_LIBRARY_PATH
 exec wine $TOP/vst/ardour_vst.exe.so "$@"