Tom Petty and the Heartbreakers keep on adding festival appearances to their 2013 tour schedule.  In addition to sets at the Bonnaroo and Hangout Music festivals, the rock legends are among the many acts who will be playing at this year's edition of the Firefly Music Festival, which takes place June 21-23 in Dover, Delaware.

Serving as headliners alongside Petty and the Heartbreakers will be the Red Hot Chili Peppers.  The bill also features a wide variety of younger rock acts, including The Avett Brothers, Alabama Shakes, Foster the People, Yeah Yeah Yeahs, The Lumineers, Vampire Weekend and MGMT.

Tickets for the event go on sale on today at 12 p.m. ET.  Visit FireflyFestival.com for more information.

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