Green Day is an American rock band formed in the East Bay of California in 1987 by lead vocalist and guitarist Billie Joe Armstrong, together with bassist and backing vocalist Mike Dirnt. For most of the band's career they have been a power trio[4] with drummer Tré Cool, who replaced John Kiffmeyer in 1990 before the recording of the band's second studio album, Kerplunk (1991). Before taking its current name in 1989, Green Day was called Blood Rage, then Sweet Children. Shop Green Day Merch Here! #greendaymerch #greendaymerchandise