I was running around TLG using up a perfume, then decided to fight a captain because why not. The battle music started fine, and then it started again. 2 battle songs, and one slightly behind the other, which got annoying pretty fast. I finished the battle and hoped that would fix it, but one layer of the battle music stuck around outside of battle and in other battles as well. I left the grove and that fixed it, but might as well post it here.

This can sometimes happen if you get into multiple fights too quickly back to back. There's like a ~1 second required time for the music to switch from explore to battle or vice versa. And for some reason that I've never been able to resolve, if there's an overlap of those switches, it like doesn't 'end' the first so now you get multiple versions of the music playing.

A simple reload of the page should fix it though if it ever happens again.

weird, thanks for the fix