If the jam don't allow me to do this, i'm allowing myself, no problem. Music is not one of my talent, I credits artits, i don't make money on their works, so everthing is fine. ¯\_(ツ)_/¯
All assets have to be created during the jam. It's not a copyright issue, it's a jam rule. So if a game isn't within the jam's rules it'll be removed from the jam. After the jam is over you can re-add the music