Lollapalooza 2015 has announced its lineup, with Paul McCartney, Metallica, and Florence + The Machine filling the headliner positions. Among the other names at the top of the billing include Sam Smith, The Weeknd, Bassnectar, alt-J, Kaskade and A$AP Rocky.

The headliners are certainly a divergence from last year's lineup, and may have surprised a few analysts in the process. McCartney's name always has to be considered a surprise-you simply can't call the biggest name among living musicians anything less. He'll be adding a Lollapalooza notch to his belt, to add to his Coachella and Bonnaroo performances. Metallica will undoubtedly be the most controversial name on the list, just as they were at Glastonbury last year, but if any American festival were to feature a metal act prominently, it would be Lolla; after all, its roots lie in the heavier grunge era. Florence + The Machine are less than surprising, considering their appearances elsewhere during festival season, but the fact that they're in the top three "big" headliners is a surprise. Perhaps the McCartney booking may have left Perry Farrell and co. cash-strapped this year. Still, a standout act.

The Chicago Tribune has already got the dates (but not the actual schedule) pegged, which you can check out below. Check out the full lineup at the festival's website.

FRIDAY, July 31: Paul McCartney, The Weeknd, alt-J, Alabama Shakes, Kaskade, Dillon Francis, Gary Clark Jr., Flying Lotus, Hot Chip, the War on Drugs, DJ Snake, Sylvan Esso, MS MR, Tove Lo, Glass Animals, St. Paul & The Broken Bones and more.

SATURDAY, August 1: Metallica, Sam Smith, Alesso, Tame Impala, Kid Cudi, Brand New, Carnage, G-Eazy, Walk The Moon, Tyler The Creator, The Tallest Man on Earth, Banks, Chet Faker, Sturgill Simpson, Death from Above 1979, Toro y Moi and more.

SUNDAY, August 2: Florence + The Machine, Bassnectar, Of Monsters and Men, A$AP Rocky, TV on The Radio, Nero, twenty one pilots, Nicky Romero, Kygo, Marina and The Diamonds, FKA Twigs, Lord Huron, Gogol Bordello, Stromae, Odesza, Logic, The Chainsmokers and more