Once you have recorded or imported the material that will make up a session/piece/composition, it will generally become time to edit it. You can add/remove material at any time, and/or modify the mix if you desire. But editing tends to be a distinct focus during the "middle" part of working on an arrangement, and has its own particular set of tools and approaches. This section of the manual covers the editing tools you will probably use all the time; see for coverage of more specialized tools and techniques.