Always have music running through my head. Used to be very difficult when I was rehearsing a show.
Now, I just have to be careful not to listen to something I like too often or it gets stuck. Even worse, just PART of it gets stuck and plays over and over and over and . . . well, you know.
Funny thing, the day after I closed said show, the music would be gone until it snuck back in some insidious, evil way ( like the opening chords were the same as the sound of wind blowing through a car window.)
(from "How Stuff Works") Experts say the culprits are earworms (or "ohrwurms," as they're called in Germany). No, they're not parasites that crawl into your ear and lay musical eggs in your brain, but they are parasitic in the sense that they get lodged in your head and cause a sort of "cognitive itch" or "brain itch" -- a need for the brain to fill in the gaps in a song's rhythm.
When we listen to a song, it triggers a part of the brain called the auditory cortex. Researchers at Dartmouth University found that when they played part of a familiar song to research subjects, the participants' auditory cortex automatically filled in the rest -- in other words, their brains kept "singing" long after the song had ended (source: Prokhorov). The only way to "scratch" brain itch is to repeat the song over and over in your mind. Unfortunately, like with mosquito bites, the more you scratch the more you itch, and so on until you're stuck in an unending song cycle.
There are many other theories about why songs get stuck in our heads. Some researchers say stuck songs are like thoughts we're trying to suppress. The harder we try not to think about them, the more we can't help it. Other experts claim that earworms are simply a way to keep the brain busy when it's idling. Just as there are many theories, there are many names for the phenomenon. It's been called everything from "repetunitis" to "melodymania."
James Kellaris, a marketing professor at the University of Cincinnati College of Business Administration, has done research on earworms and brain itch, and he's found that as many as 99 percent of us have fallen prey to them at one time or another (source: BBC News). Kellaris says women, musicians and people who are neurotic, tired or stressed are most prone to earworm attacks. With musicians, it makes sense because they're listening to music continuously, but Kellaris isn't sure why women are more susceptible to earworms
Don't worry if you keep getting songs stuck in your head -- it doesn't mean there's anything wrong with you. However, if you actually hear music that isn't there (instead of just thinking about it), see a psychologist or other mental health professional. It could be a sign of endomusia -- an obsessive condition in which people hear music that isn't really playing.