As this has been possibly planned, I'd like to see how this would turn out, as I have been wanting to use my own music for when I am fighting mobs, particularly Led Zeppelin's Immigrant Song (mainly because Thor: Ragnarok's final fight scene, Thor vs Hela's army).

Edit: Perhaps put this in a milestone, if you have plans for it?

Pushed a BETA of v3.5 to CurseForge. Note that the new version has a library dependency on OreLib (another library mod I made). Make sure you read the release notes prior to upgrade. I will be adding a resource pack containing battle music soon.