Sub Pop, the legendary indie imprint responsible for introducing Nirvana, Soundgarden, and The Shins is celebrating 20 years by putting together a benefit festival that features some of the label's hottest bands, old and new, with proceeds going to the charities designated by the artists and label.

Speculation about the possible reunions are going to clog up the blogosphere this week (Sunny Day? Afghan Whigs?), but the first confirmed reunion is Green River, an early grunge band whose lineup included Pearl Jam guitarist Stone Gossard and bassist Jeff Ament, plus Mudhoney singer/guitarist Mark Arm and guitarist Steve Turner. Other confirmed reunions are L.A.'s Beachwood Sparks, former Califone-affiliated band Red Red Meat and Seaweed. Current artists like Flight of the Conchords, Iron and Wine, Wolf Parade and many more are also on board.




The festival, dubbed SP20, will take place July 12-13 at Marymoor Park in Redmond, Washington, with a comedy version happening a day earlier at Moore Theatre. Comedians confirmed to appear at the latter event are Patton Oswalt, Eugene Mirman and Todd Barry and more

The fun doesn't stop there. Sub Pop will be releasing a series of classic reissues, starting with Mudhoney's Superfuzz Bigmuff: Deluxe Edition on May 28 and a limited run of its famous Sub Pop Singles Club. Attendees can also expect a half-pipe featuring skaters from Nike and Girl + Chocolate.
 
Discounted $30 single-day or $50 two-day passes to the SP20 festival go on sale April 26 at 12 p.m. (PST) at SubPop.com



(Read about Sub Pop artist Wolf Parade and their new 'Ritual'.)