As one might expect, Green Day‘s American Idiot musical features Broadway-ized songs off Green Day’s American Idiot album. But the show also sports four songs from the band’s latest studio effort, 21st Century Breakdown, including the second single “21 Guns”.

Recently, the band decided to record the reworked version with the cast of American Idiot. “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 shit together,” explains Armstrong. “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.”

The end result, as we discovered courtesy of Spinner, is something we’d probably describe as epic. And we’re not just saying that because there is a lot going on (the theoretical flair, multiple vocals, etc.). But judge for yourself over at Spinner.

The single will be available from all digital service providers on December 22nd. Some sort of behind-the-scenes video/documentary is also said to be in the works.