That song is stuck in my head...

Not a real deep post today, just a random question. Do any of my more cerebral folks know why certain songs get stuck in your head? Especially if you haven't heard them in a while? Where do they come from and how do we make them go away?

Yesterday it was Color me Badd's I Wanna Sex You Up. How very New Jack of me.

This morning I woke up with The Jackson's Blame It on The Boogie on repeat in my head.

By the way, my sister used to have this kickstep dead to rights. Could not tell BougieSis she was not getting her boogie on! So... Does anyone know what causes this? What's stuck in your head this fine Wednesday?