The same note can be found on different strings. Sheet music doesn’t tell you which one to play. That just one example that makes it hard
Just for clarification, I asked because GP said:
> You can’t quite run it on different hardware: unlike on a piano, the note does not uniquely determine how something is played on, say, a guitar.
> Of course, on top of that, you also have a wide range of ways to modify how you play on a guitar.
Yeah, same with the piano. And I think, with most of all instruments.
This is not possible for a guitar (and others) because there is no unique mapping between the note on the sheet and the position on the instrument.