I find it hard to even write the words “DJ Earworm.” I’ve tried to say the word “mashup” out loud alone while I’m typing, and it feels as though I’m saying, “Come see Lady Gaga perform at the Doritos Locos Tacos #Boldstage at SXSW, an activation powered by tweets.” But the fact remains: there is a man named DJ Earworm, and he created a mega-mashup called “United State of Pop 2009 (Blame It on the Pop)” that currently has fifty-five million views on YouTube and more than forty-six thousand comments. The track is not on Spotify, and, if you ever had it in your iTunes library, you had probably converted it from an MP4. But there are hidden masses among us who need only catch a glimpse of its college-Photoshop cover art—a Statue of Liberty with her dress hiked up, dancing like the recession had just been declared over—to feel an instant shiver of pathos and pain.

“Blame It on the Pop” came late in the era of mainstream mashups, which was enabled by user-friendly music-editing software and properly began with the 2001 track “A Stroke of Genius,” by the Freelance Hellraiser, which laid the vocals from Christina Aguilera’s “Genie in a Bottle” over the instrumental of “Hard to Explain,” by the Strokes. (The result, which sounds a bit like Avril Lavigne, went viral.) Five years later, a former biomedical engineer going by the name Girl Talk put out an album titled “Night Ripper,” a feat of hyperactive brilliance that feels vaguely illegal to revisit, rolling Missy Elliott into Neutral Milk Hotel into Jefferson Airplane into Juelz Santana before you can take a second sip of Sparks. DJ Earworm’s project was more targeted: “Blame It on the Pop” combines the Top Twenty-five Billboard singles of 2009 into one coherent dance track, with lyrics that hold together and that you can sing along with, from start to finish. It’s built upon the backing arrangement of the Black Eyed Peas’ “I Gotta Feeling,” a song of summer that débuted, in June, 2009, at No. 2, right behind the Black Eyed Peas’ “Boom Boom Pow.”

Melodically and otherwise, “I Gotta Feeling” is all buildup. It’s in G major, which, as the late musicologist Wilfrid Mellers put it, is the key of “blessing and benediction.” “I Gotta Feeling” avoids its dominant chord—there are no spikes of tension and release, only a simmering state of anticipation. The fun hasn’t started yet. The Black Eyed Peas only have a feeling, an intention; they’ll paint the town, they’ll shut it down, they’ll burn the roof, and then they’ll do it again. This was recession pop: an iris shot quickly blacking out the periphery of societal failure and joblessness, and narrowing our vision to a circle around a sparkler inside a bottle, inside a club. Will.i.am knew his hit was fundamentally sad. “What you hear in ‘I Gotta Feeling’? To me, that’s joy,” he told Rolling Stone. “You’re in pain, but tonight’s going to be a good night.”

Above this scaffolding, DJ Earworm constructs a Frankensteined vocal line from the rest of the year’s big singles, which are basically versions of “I Gotta Feeling”: Lady Gaga telling us to just dance, Rihanna telling us to live our life, Jamie Foxx and Flo Rida and Jay Sean telling us to binge drink at the club. Keri Hilson and Beyoncé join in on the first verse to console the listener: “Don’t worry, even if the sky is falling down. . . . No need to worry, just get back up when you’re tumbling down, down, down.” Leading into the chorus, will.i.am and the Fray split a line that makes the subtext explicit: “I got a feeling / I found God.” Salvation seemed possible in 2009: Barack Obama had just been elected, Chesley Sullenberger had performed a miracle on the Hudson, the C.E.O. of City National Bank of Florida had distributed sixty million dollars in profits to his employees. The songs in “Blame It on the Pop” are full of trust and need and longing, straddling wish and fulfillment. “It’s like I’ve been awakened,” Beyoncé sings, in a line from “Halo.” “Don’t be afraid, we’ll make it out of this mess,” Taylor Swift adds, in a sample from her hit “Love Story.” Miley Cyrus, in “The Climb,” heartbreakingly sings about every step she’s taking.

More than a decade and a half later, this sounds like one of the last gasps of the monoculture. It’s as if our country, on the cusp of micro-fracturing into algorithmically determined foxholes of individual obsession, had simply agreed, after the foreclosures and the bankruptcies and the bailouts, to put on a suit of shiny hundred-and-twenty-seven-b.p.m. optimism and go out for a good, good night. Mega-mashups went moderately viral for a while longer (see Daniel Kim’s “Pop Danthology 2012”), and DJ Earworm still does his thing each year. But there’s no sonic or thematic through line that unites Morgan Wallen, sombr, Tate McRae, Leon Thomas, Benson Boone, Olivia Dean, Rosé, and Bruno Mars—the artists in his 2025 year-end mix. There is no national mood, just a mélange of anomie, distaste, and derangement.

“Blame It on the Pop,” meanwhile, continues to attract frequent comments on YouTube, mostly from people who identify themselves as former children and who miss a time when life felt simpler and happier. Or perhaps it’s just that there were, identifiably, a couple of years when the biggest musical artists in the world were all making music that treated the general public like a coherent audience—a childish one, seeking temporary pleasure, finding blessing and benediction in the Black Eyed Peas. DJ Earworm’s big hit remains an object of peculiar power, strobing perpetually in the empty night club where the end of the aughts is stored. He released it in winter, at the close of the year, but it’s a secret song of summer for me: all promise and unpunctured optimism, a feeling of artificial forever that wasn’t meant to last. ♦