In setting an a cappella SATB piece and the (generated) rehearsal piano part, I would like to create two PDF files with different linebreaks.
Each part has many occurrences of a variable "midBarBreak" defined as { \bar "" \break } so as to break up the vocal lines at the end of the lines of the set verse. This works just fine.
Unfortunately, lilypond seems to process variables upon first reading them, so I can't use the old TeX trick of \let \this \that; nor does \noexpand have a lilypond cognate that I can find. Nor yet do I see any way to incorporate logic into the variable (e.g., if in ChoirStaff, break; if in PianoStaff, ignore). I suspect it's there, somewhere, but I'm not enough of a schemer to see how to use, e.g., ly:context-parent.
So, since TeXish methods don't work, I thought I'd ask if there's a lilypondish way to do this.
Thanks in advance, Fred
-- The things that make us happy make us wise. -- John Crowley, Little, Big