Coachella 2014's Cutest Cameo? Beck's Mini-Me Son

Southern California's Coachella Music & Arts Festival was a cameo-filled affair this year, with surprise appearances by everyone from Beyoncé, Gwen Stefani, and Mary J. Blige to Slash, Drake, and even Justin Bieber. But the cutest cameo of the weekend took place Sunday during Beck's Main Stage set, when he was joined by his adorable lookalike son, 10-year-old Cosimo.

[Photo: Biggest Surprise Guests in Coachella History]

Beck played the very first Coachella in 1999, five years before Cosimo was even born, and though the alt-rocker made a couple surprise Coachella cameos himself in the years since, this was only his second official appearance at the festival. "Fifteen years later, here we are, on the same stage, with the same band," Beck told the delighted crowd. "Justin Meldal-Johnsen on the bass, Gus [Seyffert] on the keyboards, Joey Waronker on the drums, Smokey Hormel on the guitar, Roger Manning on the keyboards... and we've got someone new. We've got Cosimo on the tambourine up here!"

Cosimo's sweet introduction begins around the 50:40 mark below:

It was a nostaglic night in many ways. Beck opened with the dream-of-the-'90s double-wallop of "Devils Haircut" and "Loser," and then, maybe to give his own nod to Coachella's increasing embrace of electronic/dance music and to the genre's auspicious beginnings, he slipped a snippet of Giorgio Moroder and Donna Summer's "I Feel Love" into his 2006 hit "Think I'm in Love."

Beck's set, one of the best of all Coachella weekend, ran the gamut from his somber new single "Blue Moon" to, most amazingly, his rarely played "Midnite Vultures" slow-jam "Debra." Unfortunately, when he went over his set time by four minutes, his sound was cut off, right in the middle of the call-and-response, famously designer-jeans-referencing section of "Where It's At."

This was an appalling lack of respect for a Coachella O.G., but Beck kept on dancing, and so did his audience — and so did Cosimo, as he joined his dad and his "bandmates" in a group hug and they shuffled offstage.

Follow all of Yahoo Music's Coachella and other festival coverage here.

Follow Lyndsey on Twitter, Instagram, Google+, Amazon, Tumblr