Three tracks--"21 Guns," "Know Your Enemy," "East Jesus Nowhere"--will be released as downloadable content on July 7, with word that "additional Green Day songs and projects will be announced at a later date." The band is perhaps best known for "Good Riddance (Time of Your Life)," a song immortalized in numerous graduation ceremonies, countless video montages, and the Seinfeld series finale special.

"Green Day not only rock hard, but are also epic storytellers," said Van Toffler, president of Harmonix owner MTV. "Their message and their music have been the voice and sound of this generation."

The extent of those additional Green Day "projects" is unknown, though Harmonix has previously released an AC/DC-specific edition of Rock Band, with the company currently prepping The Beatles: Rock Band for its September 9 release and working on a Pearl Jam-specific Rock Band entry that's slated to arrive at some point in 2010.