True auditory torture:

Two days ago, I went into a grocery store. They were playing Christmas music, already. That Alvin and the Chipmunks song came on.

This song has been going through my head for the last two days now, despite listening to other music to try to drive it out. Even better, I only remember a very small amount of the lyrics, so it's basically the same two or three lines playing over and over and over again.