Green Day is a band.
Green Day . For much of the group 's career , the band has been a trio with drummer Tré Cool , who replaced former drummer John Kiffmeyer in 1990 prior to the recording of the band 's second studio album , Kerplunk ( 1991 ) . The band 's rock opera , American Idiot ( 2004 ) , reignited the band 's popularity with a younger generation , selling six million copies in the U.S. . On April 18 , 2015 , the band was inducted into the Rock and Roll Hall of Fame as a part of the 2015 class in their first year of eligibility .