Erykah Badu, the Roots and Big Boi will rep hip-hop and R&B at Outside Lands this summer. The music festival, now in its fourth year, takes place at San Francisco's Golden Gate Park from August 12 through 14.

Headliners for the fest include Muse, Phish and Arcade Fire, while rock acts like MGMT, the Black Keys, the Decemberists and John Fogerty will also take the stage. More artists will be announced in the coming months. Three-day passes for the festival -- run by the same folks who throw the Bonnaroo event every June in Tennessee -- go on sale April 14 and start at $175.00, with a VIP three-day ticket maxing at $450.00.

Badu has been hitting the festival circuit hard the past year. She played Lollapalooza last August, and is billed for this weekend's Coachella lineup. Big Boi, who won over both hip-hop and indie rocker hearts with his solo debut album 'Sir Lucious Leftfoot: The Son of Chico Dusty,' recently announced that he was in the studio working on its followup with Swedish electro-rockers Little Dragon, who will also play the San Fran festival as well.

"It's a funk crusade man," Big Boi told the BoomBox about his sophomore album, titled 'Daddy Fat Sax: Soul Funk Crusader,' in January. "The whole thing is really about just putting out good music. Being that a lot of music don't get the exposure it's supposed to get, you gotta stay online, stay on the conveyor belt and it's quality over quantity. The next album is coming, I'm five, six songs into it."

Watch Big Boi's 'General Patton'
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