I have been writing some music (mostly for classical guitar) and have been engraving it with lilypond (fantastic tool for free quality engraving). I want to put all of these compositions into a git repository and release them to the world under a permissive license. I would like to pick a copyleft license a la GPLv3, but cursory research has not turned up much.

My question is should I use a license for code, eg GPLv3, or for more creative works, eg Creative Commons? Any advice would be greatly appreciated.

EDIT: I have now published them under CC-BY-SA-4.0 at https://git.techiedamien.xyz/TechieDamien/MusicDump.