Lollapalooza [ tickets ]--which unveils its new, two-day format this summer-- will feature a headlining set from Morrissey [ tickets ] on the event's first day, and String Cheese Incident [ tickets ] will top the bill on day two.

Rounding out the day-one roster are Sonic Youth [ tickets ], Le Tigre, Modest Mouse, Black Rebel Motorcycle Club, Broken Social Scene, The Walkmen, Danger Mouse, The Datsuns and Sparta.

Day two will feature The Flaming Lips [ tickets ], Gomez, The Polyphonic Spree, The Coup, Sound Tribe Sector 9, Elbow and Wheat.

DJ Peretz (a.k.a. tour co--founder/Jane's Addiction frontman Perry Farrell), Mass Gaming and Just beCauses will perform on both days.

PJ Harvey will grace the day-one roster on select dates, according to the event's website.

The full tour itinerary has not yet surfaced, but the outing is scheduled to begin on July 14-15 in Auburn, WA.

Tickets for the run's second stop--July 17-18 in Mountain View, CA--hit the box office on Sunday (5/2), according to promoters.

Additional details will be announced soon, according to the Lollapalooza website.