At the age of 12, Tre Cool became a member of the band The Lookouts[?]. Their album attracted some attention, and Tre began performing at an early age at the Berkeley, California punk club 924 Gilman Street[?]. In 1987, Armstrong (15 years old) and Dirnt (16 years old) formed The Sweet Children, with Armstrong on lead vocals and guitar and Dirnt on bass and backing vocals. They began playing in 1988 at Rod's Hickory Pit in Rodeo, California. In 1989, the Children renamed themselves Green Day, after their first semi-successful song. They soon added Al Sobrante[?] (born John Kiftmeyer), and went looking for a record deal.
The Lookouts were performing on punk label Lookout Records[?], headed by Lookouts lead Lawrence Livermore[?]. Green Day signed with Lookout in 1989, and released their first EP, 1,000 Hours and Slappy[?] in 1990. The next year, they produced the album 39/Smooth[?] and released it in 1991. Al Sobrante left the band at this point, and was replaced by Tre.
Green Day kicked off a national tour the day after Dirnt graduated from high school in 1990 before Slappy[?], then returned to the studio to produce their second album, Kerplunk[?], in 1992. The group signed with Reprise Records in April 1993, leaving Lookout on friendly terms. They released their first Reprise album, Dookie, in February 1994. Within a couple of months, extensive MTV airplay for the videos "Welcome to Paradise[?]" and "Longview" had established the album, and the band, as successes.
The band joined the lineups of both the Lollapalooza[?] Festival and Woodstock 1994. Green Day's Woodstock gig included a gigantic mud fight between the band and the audience, leading to a melee which led to Dirnt's losing his front teeth.
They recorded a single called "J.A.R.[?]" in 1995, and followed it up with the album Insomniac. Though the album didn't approach the success of Dookie, it still sold several million copies in the U.S. Their third major label album, Nimrod, was released in 1997, and Warning in 2000.