is it possible to change midi channels in the middle of a song ?.
Is it possible to specify midi channel numbers for a given voice or switch channels in the middle of a song in lilypond ?.
E.g. Pipe Organ software like Hauptwerk and Aeolus require Pedals, Manuals I, Manuals II, Manuals III on separate channels. Thus can switch midi channels for "solo" bit or switch soft passages to "swell" manual, etc...
It will be easy to render audio for Pipe Organ music typeset using lilypond than editing each midi file with an external editor and process using Hauptwerk/Aeolus.