Lukas-Fabian Moser <l...@gmx.de> writes: > But: Whether you use music-map or map-some-music, your helper function > (your lambda) is expected to return the new music into which the given > argument m should be transformed. So in any case, your lambda function > should return music - in the trivial case, it could return m itself > without change, but in the long run, you want to return a new > note-event, i.e. (make-music 'NoteEvent ...). > > For this, it will come in handy that it's possible to do > > (make-music 'NoteEvent m) > > i.e. create a new NoteEvent that takes its 'pitch (which you're going to > overwrite using an additional 'pitch ....), 'articulation etc. > properties from m. (This is explained somewhere in Jean's guide.)
There is no necessity to return a new NoteEvent; you can just change pitch on the existing one. Music functions are allowed to modify their music arguments in place. -- David Kastrup
