On the opening night of the 12th Coachella Valley Music & Arts Festival – as over 75,000 fans gathered in the California desert for 190 acts, including Arcade Fire, Kanye West, Kings of Leon and the Black Keys – one of the world's most famous faces must have seemed like a hallucination among the deafening boom and jittery strobe lights of Dutch DJ Afrojack's set. But Paul McCartney was totally real: After headlining the festival in 2009, he jetted in this year as a fan. "We were in the thick of it, man," he says. "I'm usually playing the place. I never get to wander around, so it was great fun to see it from the other side. We went in and got out late."
The techno-fueled Sahara tent could itself be a major electronic-music festival – but at Coachella it's just one of six huge stages, surrounded by palm trees, otherworldly artwork, stark desert mountains and barely clothed starlets. On the massive main stage, Night One culminated in amped sets by the Black Keys and Kings of Leon. The Kings, who returned after playing a sundown set in 2007, picked up energy as they tore into older, faster tunes like Aha Shake Heartbreak's "Pistol of Fire." "I've never been into a big light show," Kings frontman Caleb Followill said backstage. "But when you're in the desert, you want to get some visuals going, especially for the people in the crowd on their drugs."
Saturday offered an even more intense multisensory spectacle with Animal Collective's supremely odd animations for their free-form set. Capping the night, Arcade Fire returned to the festival where they were first anointed the Next Big Thing in 2005 for an epic, U2-scale assault of a headlining set. During a huge version of "Wake Up," 2,000 white orbs were released into the crowd and began glowing in hypnotic flashing patterns. Not that Arcade Fire needed gimmicks: Their rivetingly sequenced set, marshaling the most cathartic songs from all three of their albums, felt like yet another coronation moment for the band.
A few hours earlier, Mumford & Sons played to a main-stage crowd nearly comparable in size and intensity. "This is going to be the biggest show we will have ever played, which I only found out a couple of days ago," frontman Marcus Mumford told Rolling Stone before their set. "It's quite scary, but fun." The British crew, with an ace horn section in tow, leaned into hits from its smash LP, Sigh No More, and broke out a few earnest new anthems.
But even on the festival's most thematically unified day, there were plenty of other sounds echoing through the desert, from Erykah Badu's cosmic R&B and the reunited Big Audio Dynamite's percussive post-punk to Lil B's bizarro hip-hop and Cage the Elephant's Nineties-inspired quiet-loud attacks.
"Normally if you play a big crowd like this, you have to warm them up," says Cage singer Matt Shultz. "Here, a crowd can never have heard of you and go as crazy as die-hard fans."
The festival's closing night was all about one man: Kanye West. His headlining performance was positively regal, from his dramatic crane-assisted entrance to the pyrotechnic blasts that punctuated his set. Rumors flew throughout the weekend that West would bring out famous friends: Rihanna, Nicki Minaj, Jay-Z. But aside from Pusha T and Bon Iver's Justin Vernon making brief cameos, no guests appeared. It was a true solo show, a stunning display of West's unmatchable charisma. "Getting to watch him as a fan, I'm like, 'Damn, this guy's on top,'" says A-Trak, who spent four years as West's touring DJ and played a packed Sahara set with his new duo, Duck Sauce. "The guy is a machine."
This is a story from the May 12th, 2011 issue of Rolling Stone.