PQ battle theme. It seems to be the only battle theme in the game I've encountered so far, excluding dungeon boss. I expect this will play several hundred times more. I'd have thrown the cartridge out the window by now if it weren't so amusing.
Holy crap, so many songs in my playlist have been deleted.
Interesting. You get a different battle theme depending on the protagonist you choose. If this were a Pokemon game, they'd have made two versions of the game and sold it separately. With a third version the next year.