Two years ago, Florence and the Machine celebrated their breakthrough year with a victory lap at the Coachella Valley Music and Arts Festival. "It was quite surreal, looking out as a performer and seeing palm trees and Ferris wheels and this amazing desert skyline in the distance," says Florence Welch. "It's such a beautiful setting." Florence return to the sprawling grounds of the Empire Polo Club in Indio, California – alongside headliners Radiohead, the Black Keys, Dr. Dre and Snoop Dogg – on the third night of the April 13th-15th festival. And one week later, all the same acts will do it again, as Coachella expands for the first time to a two-weekend blowout. Adds Welch, "I can't wait!"
Over the past 13 years, Coachella has grown into one of the coolest parties in America, where top-flight rock acts and DJs mingle with A-list actors and models between sets on five huge stages. "You get to see bands you never would have gone to see, meet up with old friends and make new friends, and all that," says ex-Oasis guitarist Noel Gallagher, who's playing Night Two with his solo project, Noel Gallagher's High Flying Birds. "I'll definitely check out Radiohead – Jonny Greenwood is a fuckin' wizard, man. And if I have time to kill, I shall be prancing around the site, acting all self-important."
Other must-see acts include the Shins, recently reunited Brit-pop heroes Pulp, reggae legend Jimmy Cliff (playing with Rancid's Tim Armstrong) and Neutral Milk Hotel singer Jeff Mangum. Electronic music is a bigger part of Coachella than ever, with global superstars from Swedish House Mafia and David Guetta to Avicii and Afrojack set to shake the Sahara tent's monster sound system. "It's the biggest show for us this year," says Sebastian Ingrosso of Swedish House Mafia, who will unveil a new lighting and stage setup at the fest. "Our production team really made our dreams come true. It's something else, man."
The move to adding a second weekend is designed to double capacity without creating crowd and parking nightmares – but some aren't crazy about it. "It's a great festival, but I don't like this," says agent David T. Viecelli, whose acts at this year's festival include Bon Iver and St. Vincent. "Duplicating the exact same experience one week later just feels odd." Fans can at least expect a significant number of artists to mix things up. "If I know there's one repeat customer, I have to change the set," says Andrew Bird, who's playing Night Two. "Otherwise I'd feel like a chump."
This story is from the March 29th, 2012 issue of Rolling Stone.