Scenes from Lollapalooza 2012

Ozzy Ozbourne at Lollapalooza in Chicago, Friday, August 3, 2012.

Lollapalooza is one of Chicago's biggest music fests, taking over downtown for three days to feature such headliners as Red Hot Chili Pepper, Black Sabbath, Frank Ocean and J. Cole. 270,000 people are expected to fill Grant Park this weekend.

Credit: CBS/Jake Barlow