I have a theory about stuck songs.

I read in a medical book that when some part of your body is irritated, then it "does its thing" to excess. For example, when a hair follical (sp) is irritated, it puts out extra oil, causing seborrhea.

My theory is that when the nerves that store a song are irritated,then they play that song over and over. How does a nerve in your brain get irritated? Well, for one thing, allergies increase the pressure of cerebro-spinal fluid, and they could be a factor.

It would be interesting to correlate the occurrence of stuck songs with allergies, strange foods, lack of sleep, and other factors that might physically stress brain cells.