Is there a widely-accepted and succinct way to indicate that a repeat and/or volta is optional, or to indicate that a section should be repeated n times where n is up to the player (within bounds)?
I want to be able to say things like
- repeat this bar/section between 3 and 7 times
- choose (zero or) one of these two voltas on the last repeat
- play section A, then one of sections B,C,D, then section E and/or F
- Da Capo if you feel like it al fine uno or fine due
so that the structure of the piece is semi-improvised, but I want to avoid cluttering the score with lots of written instructions.
I imagine contemporary classical composers and jazz musicians must do this sort of thing all the time, but I'm not very familiar with either world.
I use Lilypond and don't mind writing my own functions (within reason). At the moment I'm only interested in the typeset music looking right, I don't want to control midi output or Denemo playback or anything like that.