San Francisco’s summer music celebration, Outside Lands, has announced their 2011 lineup. This year features headliners Muse, Phish (jamming for two sets), Arcade Fire and The Black Keys and also includes The Decemberists, MGMT, Roots, Grouplove, Toro Y Moi, Big Boi, Mavis Staples, and legend John Fogerty, plus many more. This year’s festival will be held August 12th-14th. Tickets go on sale this Thursday the 14th at noon, PST. To purchase tickets, see the complete lineup or get all the details, head over to Outside Lands’ website.