The one thing I don't know how to do is to declare the relative pitch
globally. Thus, each music variable looks like
movement1_part1 = \new Voice \relative c'' { notes, notes, and more notes }
The difficulty is that I want to re-set the second part for a bass
instrument, so it might start off as
movement1_part2 = \new Voice \relative c { notes, notes, and more notes }
Perhaps you could use \transpose like
\transpose c'' c {
\movement1_part2
}
to get what you want without changing your initial variables ?
Hope I don't misunderstood the point.
Cheers,