British soul singer Michael Kiwanuka (AP Photo/Jack Plunkett).Fiona Apple (AP Photo/Jack Plunkett).Colombian singer Juanes performs a Woody Guthrie song (AP Photo/Jack Plunkett).Snoop Dogg (AP Photo/Ricardo B. Brazziell, American-Statesman).Bruce Springsteen, left, performs with Steven Van Zandt, and Patti Scialfa (AP Photo/Jack Plunkett).Santigold performs at the Fader Fort (AP Photo/Jack Plunkett).Lil Wayne (AP Photo/Jack Plunkett).James Mercer of The Shins (AP Photo/Austin American-Statesman, Jay Janner).Kyle Gass, left, and Jack Black of Tenacious D (AP Photo/Austin American-Statesman, Jay Janner).M Ward (AP Photo/Austin American-Statesman, Jay Janner).The Cult, with Ian Astbury (AP Photo/Jack Plunkett).Philadelphia's The War on Drugs, with Adam Granduciel (AP Photo/Jack Plunkett).Caroline Polachek of Chairlift (AP Photo/Austin American-Statesman, Deborah Cannon).Jack White (AP Photo/Austin American-Statesman, Jay Janner).Erika Wennerstrom with the Heartless Bastards (AP Photo/Austin American-Statesman, Deborah Cannon).Gary Clark, Jr. performs during the SXSW Music Festival in Austin, Texas on Friday, March 16, 2012.(AP Photo/Jack Plunkett).The Alabama Shakes' Brittany Howard (AP Photo/Jack Plunkett).Norah Jones performs her entire new album (AP Photo/Jack Plunkett).