There are nights when my head hits the pillow and, in the still silence of my room, the jukebox in my brian lights up and starts rifling through a stack of seconds-long clips of trending TikTok sounds.

When I first got on the app more than a year ago, I heard everything from 1978's Rasputin by Boney M. to a Fortnite-inspired parody of Estelle's American Boy. 

I heralded year two of the pandemic, walking around my apartment singing "Ten kills on the board right now, just wiped out Tomato Town," having absolutely no idea what it meant. I still don't know what it means. 

@lachlan Just wiped out Tomato Town... #fortnite#Gaming#Lachlan#chugjug♬ Chug jug with you - .

And then came Bruno. 

Like so many other people, I discovered that the hit song by Lin-Manuel Miranda from Disney's Encanto had lodged itself in my head before I'd even seen the movie. I don't have the excuse of having small children. It was thanks to TikTok that I spent the early part of the year mentally listening to segments of the song, on loop. And this is to say nothing of the ensuing mashups. It's been months, but I still periodically think about one sound that clipped a snippet from a Phineas and Ferb cartoon onto the end of the line "Grappling with prophecies they couldn't understand. Do you understand?"

A scratchy voice follows up, "Well, I'll be honest, I don't really understand," and sometimes it's the only thing playing in my brain, like conference call hold music. 

@hankgreen1 ♬ We Dont Talk About Bruno But Theres A Platypus - David T. Simon

According to a 2011 study from Finnish researcher Lassi A. Liikkanen, 90% of people get songs stuck in their head at least once a week. An article from the Kennedy Center on earworms, the term for those sticky fragments of music, notes that Germans were talking about the phenomenon at least 100 years ago, calling it öhrwurm. Researchers from Dartmouth College even found that the audio cortex in your brain activates in the same way it does when you're actually listening to the song, versus imagining it.

TikTok and earworms

Earworms are very real, not that most people need convincing. And while I've always considered myself prone to getting them, I had this suspicion that since hopping on TikTok, they were getting worse -- somehow because of TikTok.

So I reached out to a researcher who studies earworms, Callula Killingly at the Queensland University of Technology. 

"You are definitely not imagining things," she told me via email. 

It turns out that there are some reason to believe a TikTok earworm could be stickier than, say, a full song. 

Killingly told me about something called the Zeigarnik effect, which applies not just to earworms, but also holds broadly that people have a better memory for tasks that are incomplete versus finished. 

"Leaving a task unfinished results in a sense of tension, because you feel psychologically compelled to finish the task. So your mind can't let go of the task," she told me. In this case, it could be the reason why a 15-second song clip won't leave me in peace. My brain thinks it's unfinished. 

Song duration isn't the only possible explanation. 

At the height of Bruno madness, it consumed my For You page. Of course, that's probably my fault on some level. Every other video seemed to feature snippets of the song, over and over again.

That repetition could be another important factor in the potency of TikTok earworms. No one has studied TikTok earworms yet. But, Killingly said, there's other research out there exploring how repetition helps get songs stuck in your head.

"Hearing the same melody over and over via TikTok could definitely lead to some earworms," Killingly said. 

I'd also guess that naturally hooky songs are more likely to end up trending on TikTok altogether, though I wouldn't call it a hard-and-fast rule. Whether pop singles like Good 4 U by Olivia Rodrigo hit it big because of TikTok, or found success on the app because they're inherently grabby, is a matter of debate. Surely, songwriters throughout the last century have hoped to craft the kind of music that gets stuck in a listener's head. 

Hook, hook, hook

Getting hung up on a 15-second song fragment could be the terminus of all this, but it might have bigger implications for the future of songwriting. A 2021 New York Times piece from Switched on Pop podcast hosts Charlie Harding and Nate Sloan dissected how the changing media landscape is breaking down the tried-and-true verse-chorus-verse format of pop songs. With listeners' attention spans splayed across different apps, platforms and formats, there's less time to pull them in. Songs like Bad Guy by Billie Eillish, which won the 2021 Grammy for song of the year, are constructed differently. 

"To keep streaming consumers engaged, it is increasingly common for songs to begin in medias res -- with a hook, followed by a hook and ending with another hook," Harding and Sloan wrote. 

Maybe one of those hooks will end up trending on TikTok. 

One of the best examples I experienced of this was SugarCrash by ElyOtto, a song that almost immediately went viral on TikTok in August, even earning the artist, Elliot Platt a deal with RCA. The song is barely more than a minute. You could argue either that it's three very intense, condensed verses, with the a two-word chorus of "feel good," a repeat of the first, a bridge and the chorus once more, or that it's got no structure and is just a super distilled helping of the kind of goods-up-front songwriting Harding and Sloan talked about. Either way, there's no loose moment to pause the song, which is arguably a great trait to have, considering how artists get paid for streams. 

And yes, SugarCrash Is one of my many TikTok earworms. 

So where does that leave those of us susceptible to earworms in an age where we're apparently going to be getting more of them than ever? 

Honestly, I don't hate the situation, but I am taking precautions. Researchers at Baylor University found that since the brain continues to process music after it's stopped playing, listening to earworms before bed might disrupt the quality of your sleep. 

In other words, unplug the jukebox before going to bed.