It's official: Eminem, Skrillex, Kings of Leon and Arctic Monkeys will rock this year's Lollapalooza. The acts, named in a previous report by the Chicago Tribune, will be joined by Calvin Harris and reformed rap duo Outkast atop the bill at the festival, which is set for Aug. 1-3 at Chicago's Grant Park. 

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Other major acts include Lorde, Foster the People, The Avett Brothers, Zedd, Nas, Childish Gambino, Nas, Broken Bells, Young the Giant, Sebastian Ingrosso and Interpol.

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Perry's own stage will host dance acts including Krewella, Above & Beyond, Flosstradamus and The Glitch Mob.

Three-day passes are sold out, however, the festival has released a limited number of single-day passes beginning today.

Many of this year's headline acts have played Lollapalooza in the past. Eminem headlined in 2011 and is riding high off the second edition of the "Marshall Mathers LP," which debuted atop the Billboard 200 last year. Skrillex played the fest in 2011 and 2013 and just released his surprise studio album "Recess" on March 14. As for the rockers, Kings of Leon headlined in 2009 and the Arctic Monkeys last played in 2011.

Last year's leading acts in Chicago included the Cure, Mumford & Sons, the Killers, and Nine Inch Nails.

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