What the fuck is up, Coachella?" shouted Tupac Shakur as he stood alongside Snoop Dogg and Dr. Dre in the California desert on April 15th. Whispers of disbelief rippled through the 85,000-strong Coachella Valley Music and Arts Festival crowd as the eerily realistic hologram launched into 1997's "Hail Mary" and traded verses with Snoop on 1996's "2 of Amerikaz Most Wanted." With flesh-and-blood cameos from Eminem, 50 Cent, Wiz Khalifa, Kendrick Lamar, Warren G and Kurupt, plus blazing versions of West Coast classics from "Nuthin' But a G Thang" to "Gin and Juice," Snoop and Dre's monster throwdown was the peak of the three-day fest. "The first time I saw it in rehearsals, I got chills," Warren G says. "Incredible."
Not that the rest of the weekend, which kicked off April 13th, didn't rock. The Black Keys topped the main-stage festivities on Night One with a lean, revved blast of blues rock. The next night, Radiohead exploded minds with spooky new grooves ("Identikit," "Lotus Flower"), towering versions of classics ("Karma Police," "Paranoid Android") and a mesmerizing light show. And at the end, it wasn't even over: For the first time, all the artists are back for another three-day blowout one week later. "It's good," Florence Welch says. "If I really fuck up this time, there's next weekend."
All weekend, one of music's most colorful, cheerful and star-packed crowds – from rave kids and gossip-mag staples (hello, Lindsay!) to Paul McCartney – wandered the palm-studded, mountain-shaded Empire Polo Club. "It's like an Eagles album cover or something, minus the skull and Native American headdress," says Keys frontman Dan Auerbach. "Although if you looked hard enough, you'd probably see that in the audience."
With 145 acts competing for attention across five stages – including Aussie breakout Gotye, reggae hero Jimmy Cliff, reunited punks At the Drive-In and Odd Future R&B crooner Frank Ocean – bands dialed up the energy to hold a crowd. "Subtlety goes out the door," says St. Vincent's Annie Clark, who shredded through an intense Night Two set. "All of the quiet numbers, we're like, 'Nope.'"
Least subtle – and arguably most popular – of all? The Sahara dance tent, where major DJs including David Guetta, Avicii and Kaskade caused barely controlled pandemonium with apocalyptic kick drums and tingle-inducing synths. "Coachella is going to become more and more DJ-oriented - that's what the kids are into," says Guetta. "The energy in the dance tent is really insane."
This story is from the May 10th, 2012 issue of Rolling Stone.