LinuxMusicians

Alas, it seems that, in lilypond, \set Staff.midiInstrument only accepts instrument names, not numbers. However, knowing the mapping [program number <-> instrument name] in your non-GM soundfont and comparing it with the GM mapping you could try "translating" directly in the lilypond file...

Thank you all for the suggestions. I'll try them the coming weekend.

Apologies if this is in a wrong forum. Say I have midi file that has been generated with Lilypond, with the instrument 'acoustic grand' (one of the choices Lilypond has). This works with the soundfont FluidR3_GM.sf2 (e.g. if I make a wav out of the midi with fluidsynth to use with Audacity). Now say...