An Earworm Pop Song Is a Cocktail of Memory Cues

In German, the word Ohrwurm has two related meanings. It can be translated as earwig, those creepy-crawly insects that you fall asleep hoping won’t burrow into your ear canal. The figurative meaning is equally invasive: Ohrwürmer are also the songs, often of the pop persuasion, that hide out in your memory, such that you could be innocently walking down the grocery aisle, and find yourself asking the Eggos if it’s too late to say sorry now.

In a new Quartz post breaking down the basics of Ohrwürmer, Mun Keat Looi sketches out their anatomy. Basically, our minds are primed to see patterns everywhere, whether it’s animals in clouds or trails down a woodland path. Storytelling exploits this: rhyme, repetition, alliteration, and rhythm are “patterns of sound,” and they help us remember the various twists and turns of a narrative. With a pop song, you not only have those lyrical cues in place, but also the rhythmic structure — something that has a powerful, driving effect on humans the world over — and the melodic structure. That’s a potent cocktail of cues, and the most ear-burrowing tracks use them in just the right way: The musical notes have “closely spaced intervals,” meaning that the notes neighbor one another on the music scale, like C, C-sharp, and D, as Maria Konnikova notes at The New Yorker. Those notes are also held for a longer duration, like in ABBA’s “Waterloo.” If all that is layered on a simple melody with some universal, repetitive, and easily-sung-along-to lyrics, you’ve got a potential earworm on your hands.

The wormiest of songs take all that accessibility and spice it up with something surprising, Looi reports, like an unusual rhythm or an extra beat. They combine fluency and novelty, two things that brains love. That balance is all over the pop charts, even today: Drake’s “One Dance” combines a familiar, even traditional Caribbean dancehall saunter with the Toronto rapper’s singsong flow, and Sia’s “Cheap Thrills” uses a similar recipe, but with bigger drums and a more gifted vocalist on the hook. It’s a formula, sure, but it only sounds formulaic if it doesn’t work. If it does work, it’ll likely “get stuck in your head,” a phrase that speaks to the involuntary nature of the process.

That’s because, Amherst College psychologist Matthew D. Schulkind explained to Discover, music falls under “procedural memory,” which is how you remember skills, like how to hit a tennis ball, rather than “declarative memory,” or how you remember facts, like how to say “dog” in Spanish. Procedural memory “doesn’t take conscious thought,” he says. “Once you start the swing, it just happens. Similarly, once you get a song started, you don’t have to think about what comes next. You hear the first few notes of a song, and it just comes pouring out.” And the best songs are perfectly made to be poured, again and again.

How to Make an Earworm