Thanks. I just looked at
8.2.8 Different editions from one source
When I have time I'll figure \tag out. Right now looking the doc above
it isn't obvious how I would apply this to make transposition any easier
than it already is for me. I know that if I can understand objects
(which I do) that I can figure out \tag but the understanding hasn't
come yet.
Try looking at section 3.3, the string quartet example. This is a fine
example of how to use \tag, and it shouldn't be too hard to apply
what's in it to your situation.
When I have done similar things in the past, I usually have a set of
files that contain the notes to each part, usually in the easiest
possible manner from what's written in the original (so, in your
example, I would just create a different variable for each
transposition section, but in the same file), then I have a second set
of files for the parts and scores. Where this isn't as clean as using
\tag, I generally find it easier to nagivate in several smaller files
than one large file.