Mumford & Sons, Phoenix, Vampire Weekend and the Killers will top this summer's Lollapalooza festival, according to the Chicago Tribune.

The official lineup has yet to be announced, but the Tribune reports that the National and the Postal Service will also join the Chicago festival, set for Aug. 2-4.

The August date could be the last of the Postal Service's current reunion tour: the Ben Gibbard and Jimmy Tamborello project's dates currently extend from April until Aug. 2, when they'll wrap up their headlining tour with a date at the Roy Wilkins Auditorium in St. Paul, Minn.

$200 "early bird" passes for Lollapalooza will go on sale on Tuesday, March 26. Full-price $235 tickets will be available after, with a limited secret sale expected this week. The festival's full lineup will be announced in April.