21st Century Breakdown is the eighth studio album by the American punk rock band Green Day. It is the band's second rock opera, following American Idiot (2004), and their first album to be produced by Butch Vig. Green Day commenced work on the record in January 2006 and forty-five songs were written by vocalist/guitarist Billie Joe Armstrong by October 2007, but the band members did not enter studio work until January 2008.