Trent Reznor, lead singer of the band Nine Inch Nails performs at the Lollapalooza Festival in Chicago, Friday, Aug. 2, 2013. The more than two-decade-old festival opens Friday in Chicago's lakefront Grant Park.

Touche Amore preforms at the House of Blues in Boston, Mass.

Alice Glass, vocalist for Canadian electronic band Crystal Castles interacts with fans after jumping off stage during their performance at the Lollapalooza Festival in Chicago, Friday, Aug. 2, 2013. The more than two-decade-old festival opens Friday in Chicago's lakefront Grant Park.

Fans react while Mumford & Sons performs at the Lollapalooza Festival in Chicago, Saturday, Aug. 3, 2013. The more than two-decade-old festival opened Friday in Chicago's lakefront Grant Park.

Muse performs at the TD Garden in Boston, Mass.

Nick Ghanbarian of Bayside performs at the House of Blues in Boston, Mass.

Ryan Key of Yellowcard performs at the House of Blues in Boston, Mass.

Steven Tyler of Aerosmith performs on Commonwealth Ave. in Boston, Mass.

Lady Gaga performs at the TD Garden in Boston, Mass.

The Black Eyed Peas perform at the TD Garden in Boston, Mass.

Justin Bieber performs at the TD Garden in Boston, Mass.

Gerard Way of My Chemical Romance performs at the House of Blues in Boston, Mass.

The Backstreet Boys perform at the Bank of America Pavilion in Boston, Mass.

Jared Leto of 30 Seconds to Mars performs at the House of Blues in Boston, Mass.

Claudio Sanchez of Coheed & Cambria performs at the House of Blues in Boston, Mass.

Jay-Z performs at the TD Garden in Boston, Mass.

Jack Barakat of All Time Low performs at the House of Blues in Boston, Mass.

Alex Lifeson of Rush performs at the TD Garden in Boston, Mass.

Jim Adkins of Jimmy Eat World performs at the House of Blues in Boston, Mass.

Andrew McMahon of Something Corporate performs at the House of Blues in Boston, Mass.

Steven Tyler of Aerosmith performs at Thayer Academy in Braintree, Mass.