I know this post is a little old, but I figured I answer, or empathize. I have the same thing. Except it's not really the same song over and over. I don't hear made up music either, just songs that I know, or have heard at least once before. I learn music unusually quickly. I can hear a song a few times, and without even trying I'll know all the words, the beat drops, the high hats, the pauses for acapella, and all the little adlibs.