The Lollapalooza 2015 line up is out with Metallica, Paul McCartney, Bassnectar, Sam Smith, The Weeknd, Alabama Shakes, and Florence + the Machine headlining the bill.
Other bands and singers playing Lollapalooza 2015 include Of Monsters and Men, FKA twigs, Tame Impala, NERO, Kygo, Nicky Romero, The War on Drugs, Flying Lotus, Marina and the Diamonds, Tove Lo, Tyler and Alesso. You can check out the entire lineup at the Lollapalooza website but, yes, it is a good one.
Lollapalooza 2015 will be from July 31st to August 2nd. Single-day tickets have just gone on sale (at the website), three-day passes, however, have already sold out. If you want to go you may want to get over there fast, as I doubt single-day tickets will last out the day.