Why do some songs get stuck in our heads so easily? The science of earworms

If you’ve watched the movie KPop Demon Hunters and see the word “golden”, what happens?

Pause and think about it for a moment.

For those unfamiliar, nothing will come to mind. But if you’ve heard the song of the same name, you may start hearing a fragment of the tune repeating in your head, over and over. You might even mouth or sing the words “we’re goin’ up, up, up”.

Did that happen to you? If so, you just experienced “involuntary musical imagery”, colloquially known as an earworm.

More than 90% of the population experience earworms, and researchers are beginning to understand how they work, why they happen, what they tell us about the brain, and even how to get rid of them – if you want to.

Baby shark, doo doo doo

The humble earworm has taught music psychologists that repeated fragments of music are recycled from the same mental storage location. In Golden, the music accompanying the words “we’re goin’ up, up, up” is repeated several times.

The most earworm-inducing feature is “contiguous” repetition: a fragment of the music that repeats immediately and without delay, like the repeating chorus of a pop song.

Baby Shark, Kylie Minogue’s Can’t Get You Out Of My Head, and many, many other songs contain such repetition, and have gone through periods of mass exposure – another important ingredient for earworms because it increases familiarity.

When a song becomes an earworm, the mind repeats the musical phrase, seemingly indefinitely. That’s because the way music recall is organised in the mind is not like a sound file or tape recording that plays from beginning to end.

Rather, the music is efficiently organised into “pockets” based on familiarity and similarity, with some pockets recycled where possible.

Exposure to the music binds the various pockets together through the mental network, not unlike a series of instructions: “start with this introduction, play the verse through twice, then go to the chorus and repeat it four times, go to the next section, back to the verse, repeat that”, and so on.

These “instructions” are a crucial part of the earworm story.

How it’s done, done, done

Several triggers can initiate an earworm: recently having heard some or all of the song, or even just hearing or seeing a relevant phrase (like in this article), or hearing another song that sounds similar.

Habits and environmental triggers can play a role too. For example, if you’re on the bus listening to music every morning, a song fragment might jump into your head one morning even if your playlist is off.

There’s a deeper reason for this. Earworms are more likely to start their musical wriggles when a particular set of brain regions is activated, called the default mode network. The network is associated with daydreaming and mind-wandering, allowing intrusive and repetitive thoughts to surface more easily.

When it comes to song recall, this network is like a naughty, antisocial sibling who picks their favourite part of the song and spends all night in their room listening to it, over and over again.

The parts of the brain involved in focused attention that know how many times the song fragment should be played – and what should come next – are locked out of the default mode network’s room.

When a song has strong repetition, that becomes the network’s focus. The instructions for mentally replaying the song become more akin to “when you reach the end of the fragment, go back and play it again”, with the “correct” number of repetitions and the other parts of the song nowhere to be seen.

The mind is freewheeling, circling around the repeated fragment with no reason to stop.

Mamma mia, here we go again

Some researchers have found people enjoy their earworms, but there are also reports of song fragments being stuck in people’s heads for hours and even days. What if you’ve just had enough of Golden?

To evict an unwanted earworm, you need to disengage your default mode network. One method is to sing the song aloud to other people. The social engagement deters the network from activating, but at the expense of some embarrassment. So … effective, but not always optimal.

Another approach is to replace the song by another, less repetitive one, to keep the looping desires of the default mode network at bay. Happy Birthday and God Save the King are examples of songs that don’t have the kind of repetition that suits earworms.

Software company Atlassian even published a 40-second audio track that’s supposed to squash earworms, based on the principles explained above. With such a tune, there is no contiguous repetition for the earworm to hook on to.

Earworms are providing insights into how music is organised, but they can also bring pleasure by repeating the music you’re enjoying.

If you have a bad relationship with those pesky sound loops, and none of the above tips worked, here’s a final bit of advice. Listen to lots of different music and grow to love your inner earworm.

Emery Schubert receives funding from the Australian Research Council.