The topos of music is a famous example of this. Topos theory is as abstract as you can get in mathematics and there seems to be a lot to be said using this language.
I can't really comment on this since I haven't read it, but maybe someone else can chime in.
for reference, this is the actual book: The Topos of Music by Guerrino Mazzola
There are always more ways to apply mathematical concepts, particularly if you are looking for more abstract representations of music, like Xenakis or Babbitt.