Gallery: Lollapalooza rocks Chicago

Haley Reinhart performs during a Lollapalooza concert, Friday, August 3, 2012 in Chicago. (AP Photo/Daily Herald, Joel Bissell)

Dan Auerbach from The Black Keys performs at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Ozzy Osbourne of Black Sabbath performs aLollapalooza on opening day in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Steve C. Mitchell/Invision/AP)

Michael Angelakos of the electro-pop band Passion Pit performs at the Lollapalooza music festival on opening day in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Steve C. Mitchell/Invision/AP)

Artists put the finishing touches on the Perry's Stage sign at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Steve C. Mitchell/Invision/AP)

Ozzy Osborne of Black Sabbath performs at the Lollapalooza music festival on opening day in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Steve C. Mitchell/Invision/AP)

Tony Iommi of Black Sabbath performs at the Lollapalooza music festival on opening day in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Steve C. Mitchell/Invision/AP)

Members of the crowd watch The Black Keys, unseen, play at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Music fans enter the Lollapalooza music festival in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Steve Mitchell/Invision/AP)

Fans gather for a performance by Yellow Ostrich at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Fans dance their way between stages at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Alex Schaaf from Yellow Ostrich performs at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Ninja from Die Antwoord performs at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Alex Schaaf from Yellow Ostrich performs at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Fans watch a performance by Yellow Ostrich at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Jessica Dobson from The Shins performs at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

James Mercer from The Shins performs at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Fans dance their way between stages at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Members of the crowd dance at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

A couple shares a private moment at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Yolandi Vi$$er, left, and Ninja from Die Antwoord perform at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)

Haley Reinhart performs during a Lollapalooza concert, Friday, August 3, 2012 in Chicago. (AP Photo/Daily Herald, Joel Bissell) MANDATORY CREDIT; TV OUT; MAGS

The 2012 edition of the Lollapalooza annual concert series began at Grant Park, Friday, Aug. 3, 2012 in Chicago. (AP Photo/Daily Herald, Joel Bissell)

Singing artist Haley Reinhart signs a shirt during the Lollapalooza festival, Friday, August 3, 2012 in Chicago. (AP Photo/Daily Herald, Joel Bissell)

Dan Auerbach from The Black Keys performs at Lollapalooza in Chicago's Grant Park on Friday, Aug. 3, 2012. (Photo by Sitthixay Ditthavong/Invision/AP)