stave compression, music reuse, etc.

[Kieren Richard MacMillan]

Hello, all --

I write choral music that includes many different textures, including 
the following: extended sections in "unison" (i.e., SA in unison, TB in 
unison an octave lower), which can be written on a single line; 
homophonic sections, which can (often) be written on two staves; and 
polyphonic sections, which require four (or sometimes more) staves. In 
a single engraved score, I sometimes need to switch between these 
"modes", in order to improve readability, reduce errors, and save space.

Is there any way that I can take advantage of Lilypond to assist with 
this? For example, can I assign the same music to four different 
Voices, and decide at compile time whether the four voices should be 
outputted to one, two, or four lines?

Thanks,
Kieren.