Lollapalooza 2011: 11 Things Seen & Heard Sunday
The Foo Fighters headline Sunday night of Lollapalooza 2011.

Lollapalooza's 20th anniversary is now in the history books, but we got photos of everything that went down Aug. 5-7. 2011 in Chicago's Grant Park.

On Sunday, Foo Fighters gleefully rocked out in the rain and fans moshed in the mud for Artic Monkeys. On Saturday, Eminem roared into Grant Park with Bruno Mars, Royce da 5'9" and Sylar Grey and Cee Lo rocked a male dominatrix get-up while he belted a Journey cover. Friday featured Coldplay's lasers duelling with Muse's fireworks. But the mega-bands weren't the only ones who impressed.

PERFORMANCE PHOTOS: Lollapalooza 2011

From Girl Talk to Ratatat, Bright Eyes to Pete Wentz's Black Cards, acts across all genres took over Chicago's Grant Park. Check out all the action from the 20 in our photo gallery, linked above, which includes not only performance photos but candid action on the Lolla grounds as well. And be sure to check out the photos from the backstage Billboard photo studio below.

LOLLA PORTRAITS: Shots From Our Backstage Studio

Lollapalooza 2011 Main Page