Chicago's Grant Park will be filled to the brim if what the Daily Swarm says is true: that Lady GaGa, Green Day and the recently reunited Soundgarden will headline the three-day festival.

According to the site, "multiple sources" confirmed the GaGapalooza rumors, though left hanging whether or not Arcade Fire would join the bill, like they did in 2005 as their popularity was growing to fever-pitch. This year's fest will run over the weekend of Aug. 6-8.

Organizers responded to an email request for more information with no comment. They normally send official word of the lineup in the spring.

Lollapalooza, which was formerly a roving festival, had its first, completely sold out weekend in sturdy Chicago a couple of summers ago when Radiohead came to town; no other band competed at the other end of the field and a reported 75,000 people showed up for it. Last year also sold out when final, last minute, one-day sales went for Jane's Addiction, Depeche Mode, Tool and Kings of Leon.

Soundgarden has confirmed no shows in 2010 yet, though did announce its reunion via Twitter over New Year's.

Lady GaGa is currently on her Monster Ball tour overseas through April. She actually performed on a much smaller stage at Lolla in 2007, before "The Fame" overtook everybody's brain.

Green Day has been quiet, touring-wise, lately, though their "American Idiot" musical will soon get its Broadway debut.