CHICAGO, IL - JULY 31: Paul McCartney performs during 2015 Lollapalooza at Grant Park on July 31, 2015 in Chicago, Illinois. (Photo by Tim Mosenfelder/Getty Images)
CHICAGO, IL - JULY 31: Paul McCartney performs during 2015 Lollapalooza at Grant Park on July 31, 2015 in Chicago, Illinois. (Photo by Tim Mosenfelder/Getty Images)