The lineup for Lollapalooza 2015 has been announce, with Paul McCartney, Metallica, and Florence + The Machine set to headline. The festival takes place on July 31 – August 2 at Grant Park in Chicago, IL. Other top rock acts include Alabama Shakes, Brand New, TV On The Radio, twenty one pilots, The War on Drugs, Cold War Kids, Death From Above 1979, and more. Tickets go on sale today at 10am CT via Lollapalooza.com. – by Matt Bishop