"Earworms", some people call them. Songs that get stuck in your head and go round and round, sometimes for days, sometimes for months. For no apparent reason you cannot help yourself from humming or singing a tune by Lady Gaga or Coldplay, or horror upon horrors, the latest American Idol reject.
To a psychologist – or at least to this psychologist – the most interesting thing about earworms is that they show a part of our mind that is clearly outside of our control. Earworms arrive without permission and refuse to leave when we tell them to. They are parasites, living in a part of our minds that rehearses sounds.
We all get these musical memories, and people appear to have different ones, according to a team at Goldsmiths University in London, who collected a database of over 5,000 earworms. True, the songs that we get stuck with tend to be simple and repetitive, but it seems we are not all singing the same number one song at the same time.
Lost in music
Neurologist Oliver Sacks wrote in his book Musicophilia that earworms are a clear sign of "the overwhelming, and at times, helpless, sensitivity of our brains to music". Music is defined by repetition, just like earworms, and this might make earworms so hard to shake – they are musical memories that loop, say a particular verse or a hook, forever repeating rather than running to completion. Some people report that singing an earworm to the end can help get rid of it (others report in frustration that this does not work at all).
As well as containing repetition, music is also unusual among the things we regularly encounter for being so similar each time we hear it. Fences are visually repetitive, for example, but each time you see the same fence you will look at it from a different angle, or in different light. Put a song on your stereo and the sound comes out virtually identical each time. Remembering is powerfully affected by repetition, so maybe the similarity of music engraves deep grooves in our mind. Grooves in which earworms can thrive.
Another fact about earworms is that they often seem to have something interesting or usual about them. Although they will often be simple and repetitive bits of music, tunes that become earworms have a little twist or peculiarity, something that makes them “catchy”, and perhaps this is a clue as to why they can take hold in our memory system. If there was nothing unique about them they would be swamped by all the other memories that sound similar too.
Slave to the rhythm
If you have got a particularly persistent earworm you can suffer an attack of it merely by someone mentioning the tune, without having to hear it. This proves that earworms are a phenomenon of long-term memory, rather than merely being a temporary “after-image” in sound.
But this is not the whole story. Human memory researchers have identified so called "slave systems" in our short-term memory, components of the mind which capture sights and sounds, keeping them alive for a short time while we focus on them.
One slave system is the "mind's eye", capturing visual information, another is the "inner ear", the part we use for remembering phone numbers, for instance. It is this second part that seems to get infected with earworms. Rather than rehearse our plans for the day, idle thoughts, or lists of things to remember, the inner ear gets stuck on a few short bars of music or a couple of phrases from a song. A part of us that we normally do not have to think about, that should just do what we ask, has been turned against us, tormenting us with a jukebox request that we never asked for.