Why Do We Get Songs Stuck In Our Heads?

No you're not going crazy...You know how it is, you hear a tiny
snippet of a song on the radio in the morning and even if you hate the
band or artist you find yourself singing it in an endless torturous
loop for the rest of the day. Why does this happen? There could be a
song a wedding DJ played three weeks ago that you don't know the name
of or what the lyrics are but you will find yourself still
inexplicably humming the tune while brushing your teeth one night.
Here are a few explanations:Ear GremlinsNo seriously it is a real
explanation. Ear gremlins are an itch your brain develops when it
hears a song. Your auditory cortex hears a tune and thanks to the way
the rhythm goes your brain can't help but fill in the gaps. Like a
cliff-hanger in a soap opera, your brain hears a story or a rhythm and
because the next part of the song or the exciting moment in the story
isn't there your clever brain can't help but try to fill the gap. With
a soap opera you can but speculate but with a song and a rhythm it is
easier for your brain to make something up.Brain BusyYour brain is
like any live band for wedding receptions, it will keep going no
matter how many people or thoughts have left the venue. Your brain has
no off switch and when you are doing a task which leaves part of your
brain idle there is a theory that in order to keep your brain ticking
over it gives itself something easy to do, like humming the easiest
rhythm in your memory. Unfortunately for you though that rhythm might
be Abba 'Waterloo' or Take That's 'Could it be magic?' which some
people might find quite annoying. A bit like a group of guerrilla
cover bands that sneak into your garden at night and torment you with
their 80's polka favourites.Suppressing ThoughtsOne further theory is
that by practically forcing you to hum a tune, your brain is
suppressing thoughts which would either be distracting from your
current task or would lead you to some other train of thought which
your subconscious does not want to think about. Not necessarily a
traumatic childhood event or anything, probably more like paying the
gas bill or remembering to buy pineapples or even thinking about that
tribute band you went to see last week which you don't want anyone to
know that you like so try not to think about in case you end up
humming the tune out loud...hmm hmmm hmmmmmm...d'oh!