/usr/share/texmf/tex/lilypond is in lilypond-data 2.14.2-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/texmf/tex/../../lilypond/2.14.2/tex
/usr/share/texmf/tex/../../lilypond/2.14.2/tex