A really neat idea! The idea kinda reminds me of the drummers and flutists who would march into war with the soldiers to pump them up.
In it's currently implantation, I see no reason why I can't simply have all of the music options active at the same time, which sort of defeats the gameplay portion of it. But I like that you listed all the ideas you had if there were more time to implement them - that's the whole beauty of game jams in my opinion. I think you have a really neat and unique idea here with a lot of potential for growth. Great work :)