Paul McCartney, Metallica + Florence and the Machine to Headline Lollapalooza 2015

The 2015 lineup for Lollapalooza has been announced, and for the most part, it follows in the footsteps of other festivals before it this year. Paul McCartney, Florence and the Machine, Sam Smith, Tame Impala, Alt-J, Death From Above 1979, TV on the Radio, Alabama Shakes, the War on Drugs and more are all supporting the latest edition of the iconic fest, slated for July 31-Aug. 2 at Grant Park in Chicago.

The biggest surprise in the lineup is McCartney’s co-headliner, Metallica, whose only other North American date is Rock in Rio USA in Las Vegas on May 9.

Early bird and general admission three-day passes are already sold-out. General admission one-day passes are on sale (for $110 each) right now. Get more details at this location.

Lollapalooza -- which was initially conceived in 1991 as a farewell tour for Jane's Addiction -- has expanded into an internationally-acclaimed event, already taking over South America earlier this year and slated for its first-ever European installment in September.

Festival organizers have shared the official poster for this year's Lollapalooza, designed by Tony Fitzpatrick to "capture the spirit of Chicago's legendary musical history -- and Lollapalooza's place in the narrative." Most recently, you likely saw Fitzpatrick's work on the cover of Steve Earle's latest studio album, Terraplane. Check out the poster here.

You can find the full line-up and schedule at Lollapalooza’s official website, and make sure to check out all of the bands below: