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.