Green Day is an American punk rock band formed in 1987 by lead vocalist and guitarist Billie Joe Armstrong and bassist Mike Dirnt. For much of the band's career, they have been a trio with drummer Tré Cool, who replaced John Kiffmeyer in 1990 prior to the recording of the band's second studio album, Kerplunk (1991). Green Day has sold more than 85 million records worldwide. 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.