lilypond uses TeX to create "engraved sheet music." So I'd imagine it would
create PDFs that could be converted to other formats.
From a cursory look it appears that music21 has good support for MusicXML so
that might be a way to interoperate between the pieces.
Sample (unencumbered) score
Installing music21 is trivial -- just use "pip install music21". I
tried with SMC:
https://cloud.sagemath.com/projects/4a5f0542-5873-4eed-a85c-a18c706e8bcd/files/support/2015-12-08-141248-music21.sagews
However, to display music, one would need a way to get a png or svg
image written to a file;
