Took from original MUGEN select.def: ; - music
; Set the paramvalue to the name of the music file to use
; as the BGM for that character. This overrides the bgmusic
; parameter in the stage's .def file, so you can re-use the
; same stage for multiple characters, but have a different
; BGM playing for each person.
; Example:
; kfm, stages/mybg.def, music=sound/song.mp3