zmusic (library for music support in games)

ZMusic is GZDoom's music system separated as a stand-alone music
library, providing a unified interface for its components.

Note: Technically, fluidsynth is optional, but it's *very* highly
recommended. I've listed it as required, for the convenience of
sbopkg/sbotools users. If you're reading this, you are not a robot,
and you can make up your own mind.
