Right now, somewhere in your brain, a song is waiting to ambush you. Maybe it's a jingle from a commercial you haven't seen in years, or three notes from a pop chorus you don't even like. It doesn't matter. Your auditory cortex has its own playlist — and you didn't get to approve it.

Scientists call these involuntary musical images. Everyone else calls them earworms. About 90% of people experience them at least once a week, making them one of the most common forms of involuntary cognition we know of. They're undeniably annoying. But they also reveal something genuinely fascinating about how your brain processes sound, stores memory, and handles the nagging feeling of unfinished business.

Your auditory cortex sits in the temporal lobes, just above your ears. Its job is processing everything you hear — conversations, car horns, birdsong. But it has a peculiar habit. When it encounters a catchy musical phrase, it can get stuck replaying it like a turntable needle caught in a scratched groove.

This happens because music activates a powerful feedback loop between your auditory cortex and your motor planning regions. When you hear a song, your brain doesn't just passively listen. It quietly rehearses the rhythm, the melody, even the tiny muscle movements you'd need to sing along. This motor-auditory circuit is what makes music so uniquely sticky. Your brain is essentially humming along without your permission.

The catchiest earworms tend to share specific features: simple, repetitive melodies with slightly unexpected intervals. Think of Baby Shark or the opening notes of Beethoven's Fifth. Your brain loves patterns it can almost predict — but not quite. That sliver of unpredictability keeps the loop spinning, because your neural circuits keep trying to resolve the pattern. It's like your brain is a dog chasing its own tail, except the tail is a melody you heard at a supermarket in 2014.

Takeaway

Your brain doesn't just listen to music — it secretly performs it. Earworms are the sound of your motor cortex rehearsing a concert you never agreed to give.

In the 1920s, a psychologist named Bluma Zeigarnik noticed something peculiar about restaurant waiters. They could recall complex orders with perfect accuracy — but only until the food was delivered. The moment a task was complete, the memory practically evaporated. Unfinished tasks, however, lingered stubbornly. Decades later, researchers discovered your brain treats incomplete songs in exactly the same way.

This is why the chorus you can't quite finish haunts you far more than the one you know by heart. When your brain encounters an incomplete musical pattern, it flags it as unresolved business. Your prefrontal cortex — essentially your brain's overworked project manager — keeps the item on its mental to-do list, replaying it over and over in a persistent, slightly obsessive attempt to find closure.

Think about it like leaving a sentence half. See how that bothered you? Your brain craves completion the way your lungs crave air. Musical phrases trigger the exact same itch. Research has found that people who hear a song cut off mid-phrase experience significantly more involuntary replays than those who hear the complete version. Your neural circuits aren't torturing you on purpose. They're earnestly trying to finish a job they started.

Takeaway

Unfinished business sticks. Your brain replays incomplete songs for the same reason you remember unsent emails and half-told stories — it can't file away what it hasn't resolved.

So how do you actually evict an unwanted earworm? Neuroscience offers some surprisingly practical answers. The most effective technique is called cognitive engagement — giving your brain a different puzzle to chew on. Anagram games, Sudoku, or reading something moderately challenging can redirect the neural resources your auditory cortex has been monopolising. The sweet spot is a task engaging enough to compete but not so difficult it becomes frustrating.

Another proven method is the cure song approach. Researchers at Western Washington University found that listening to an earworm all the way through — completely, from beginning to end — often breaks the cycle. Remember the Zeigarnik effect? Completion signals your brain that the job is done. The loop loses its urgency, and your auditory cortex finally moves on to other things.

Then there's chewing gum. It works, and the reason is wonderfully strange. Your motor cortex uses some of the same neural pathways for jaw movement as it does for subvocal rehearsal — that quiet inner singing your brain does when replaying a tune. Chewing essentially jams the signal by occupying those motor circuits with a competing physical task. It's the neural equivalent of changing the channel by accidentally sitting on the remote.

Takeaway

You can't silence an earworm by ignoring it, but you can outmanoeuvre it — give your brain either the closure it craves or a more interesting problem to solve.

Earworms aren't a glitch in your software. They're a byproduct of the same remarkable neural machinery that lets you learn language, appreciate a symphony, and recognise your best friend's laugh across a crowded room. Your auditory cortex is doing exactly what millions of years of evolution shaped it to do — finding patterns and holding on tight.

So next time a song hijacks your afternoon, take a quiet moment to appreciate the engineering behind it. Then go chew some gum.