The '21 Guns' recording with Green Day alongside the cast from the American Idiot Musical will be premiering tomorrow on Spinner.com. It will be available to radio stations December 3rd, and then available for us to buy from music stores (iTunes, Amazon, etc.) December 22nd.

From the press release (full text can be read on GD.com)

[quote]We wanted to record '21 Guns' because it represents a pivotal moment in the show when the lead character, sung by John Gallagher, Jr., realizes he needs to get his stuff together," says Armstrong, who collaborated on the story for American Idiot with Tony Award-winning director Michael Mayer (Spring Awakening). "After the show wrapped, we headed straight to Oakland with the cast to record, and they sung the hell out of it. I couldn't be happier. It's great to have something out there for people to hear who didn't get to see the show.[/quote]