The organizers of one of the nation’s biggest music festivals, Lollapalooza announced their 20th anniversary lineup. This year’s festival which is being held August 5-7, 2011 in Chicago’s Grant Park includes headliners Eminem, Muse, Foo Fighters, and Coldplay. Some of the other notibles include My Morning Hacket, A Perfect Circle, The Cars, Bright Eyes, Arctic Monkeys, Deftones, Atmosphere, Cold War Kids, and Ok Go. You can see the entire lineup HERE. Secret Sale and Early Bird tickets are already sold out. Regular 3-day passes are on sale but they are going quickly.