Premise: 21st Century Breakdown is the eighth studio album by American punk rock band Green Day . Green Day is an American punk rock band formed in 1986 by lead vocalist and guitarist Billie Joe Armstrong and bassist Mike Dirnt . The group has won five Grammy Awards : Best Alternative Album for Dookie , Best Rock Album for American Idiot , Record of the Year for `` Boulevard of Broken Dreams '' , Best Rock Album for the second time for 21st Century Breakdown and Best Musical Show Album for American Idiot : The Original Broadway Cast Recording .
Hypothesis: Green Day is a band.
Label: ENTAILMENT