As to your question regarding the avoidance of small files, the "Using
LilyPond" guide has the following option listed for lilypond-book:
`-o DIR'
`--output=DIR'
Place generated files in directory DIR. Running `lilypond-book'
generates lots of small files that LilyPond will process. To
avoid all that garbage in the source directory, use the `--output'
command line option, and change to that directory before running
`latex' or `makeinfo'.
lilypond-book --output=out yourfile.lytex
cd out
That's not totally fabulous, but easier to clean up than if you are not
using this option.
--
David Kastrup