21st Century Breakdown

Armstrong began writing in January 2006, and by October 2007 he had written about 45 songs. Many were written on piano. The band began recording in January 2008 with Butch Vig and finished in April 2009, working across four California studios. In Hollywood they bought cheap turntables and listened to old vinyl for inspiration. Armstrong kept his lyrics guarded and only read them aloud to Cool, Dirnt and Vig in late 2008. David Bowie is credited as a songwriter on 21 Guns because its chorus melody resembles All the Young Dudes.

The album is set in three acts, Heroes and Cons, Charlatans and Saints, and Horseshoes and Handgrenades, and follows a young couple named Christian and Gloria. It debuted at number one on the Billboard 200 with 215,000 copies in a shortened three-day week, and topped the charts in 24 countries. It won the Grammy for Best Rock Album at the 52nd ceremony. Singles were Know Your Enemy, 21 Guns and East Jesus Nowhere. Walmart refused to carry it because of its parental advisory sticker and asked for a censored edition; the band said no.

Metacritic reported a score of 70 from 30 reviews. David Fricke of Rolling Stone compared it to London Calling, Quadrophenia and Zen Arcade. Alexis Petridis of the Guardian said the storyline becomes impossible to follow.