Earworms - Songs that stick in your head

Have you ever had a song stuck in your head and you just can't shift it?  Even if you don't like it, it's just stuck in your head.  This week Meera has been finding out why this happens and just how music manages to worm its way into your head.

Meera - I'm sure you've all been walking along, say to the shops or to the park, and found you're humming a song. It could be the latest track by your favourite band or a song that reminds you of someone or something. Not only is this song currently in your head but you soon realise that you've been humming it all day, possibly even all week. To find out why songs and why music stays in our memory so easily I spoke to Professor Daniel Levitin from McGill University in Montreal, who's not only an expert in the field of music perception but he's also an ex-recording engineer and record producer. To start with I had to ask, 'why do our brains remember music so easily?'

Daniel - In the jargon of our field I would characterise it as being constituted of multiply redundant, or reinforcing cues. What I mean by that is that if you're trying to remember the words there are a lot of things that constrain them. You've got the access structure, the melody, you've got a rhyming scheme. There are only certain words that will fit at the end of a line. In terms of melody, you may not remember all the notes of a melody. But if you remember the melody starts low and goes high, it might be going be-de-de-de-ri-naaaa [ascends to higher notes after a few beats].  You've got to get from one to the other, there's only certain notes that it could be. What we've learned about memory is that there's a certain aspect of human memory that's illusory. You don't remember every detail of everything. You construct some of the details at the moment of recollection. You fill in information that isn't actually in your memory with a plausible substitute. This happens all the time in music.

Meera - What about those irritating songs that stay in your head no matter how hard you try to throw them out? You know the ones I mean!

Daniel - There's a word for this. They're called 'earworms,' like those little insects that burrows into your ear canal and you can't get it out. They tend to be simple melodically and rhythmically. They tend to be the kinds of songs that the popular radio stations play and overplay. So they get stuck in there and you can't get them out. Most people aren't running around with Stravinsky in there, they're running around with Who Let the Dogs Out or, what I've had stuck in my head for the last week which is, Crazy by Patsy Cline.

Meera - Crazy isn't a bad song to get stuck in your head. I get far more annoying things like the Flintstone's theme. Can you imagine how irritating that is? Playing like a broken record in your head all day long? I had to ask him if there was a cure.

Daniel - There absolutely is! You just think of another irritating song and it pushes the first one out.

Meera - Great (!) That's not really a cure though, is it? Well, if these earworms insist on staying in our heads please tell them they serve at least some kind of purpose.

Daniel - This is a key to the evolutionary origins of music. The idea is that if a song gets stuck in your head maybe it has some evolutionary reasons to do so. Some of the anthropologists I've spoken to have told me that in certain societies this is a part of courtship. A young boy will sing a song to a young girl. The idea is a song is supposed to get stuck in her head. When he's away on the hunt, she'll remember him. They can encounter each other in the reeds for example, and he can whistle the song and she'll know it's him. Then they can go off and do whatever they do.

Meera - Hmm. So to woo your next potential partner, seems you should compose and sing them the most irritating song you can come up with. An infallible plan, I'm sure!