Vampire Weekend will headline the third annual Roots Picnic, which will also feature a performance by the Philadelphia-based Roots. The event will be held June 5 at Philadelphia's Festival Pier; tickets go on sale Friday (March 5) via

The Roots Picnic will boast a reunion performance by an as-yet-unannounced hip-hop act, but in a video posted from his Twitter page, Questlove indicates it will be along the lines of the Roots' and Public Enemy's complete performance of the latter group's "It Takes a Nation of Millions" at the 2009 installment of the event. Additionally, Two associated side projects from drummer Ahmir "Questlove" Thompson and rapper Tariq "Black Thought" Trotter will perform as well.

Also on the bill are Clipse, Mayer Hawthorne, Nneka, the Very Best, Tuneyards, Das Racist, Bajah and the Dry Eye Crew and Pattern Is Movement. In addition, Questlove will play a set with fellow Philadelphia native DJ Jazzy Jeff, while Black Thought will perform with his side project the Money Making Jam Boys, which also features Dice Raw and Truck North.

Last year's event also included performances by the Black Keys, TV On The Radio and Santigold, among others.