The headliners for the 2015 Lollapalooza festival this year make it plenty evident that the talent pool and drawing power of cutting edge talent is very shallow these days. Organizers of the annual festival that adopted Chicago's Grant Park as its permanent site have gone to Paul McCartney and Metallica to headline. Others on the July 31 - August 2 bill include Alabama Shakes, Florence & The Machine, TV On The Radio and a dozen or so other bands we've never heard of.