Back in Rodeo, Billie Joe and Mike finally got around to forming a band of their own in 1987, Performing under the name the Sweet Children, they landed their first gig that same year, playing in the lounge of Rod's Hickory Pit, the joint where Billie Joe's mom waitressed and Mike worked as a cook. The Sweet Children name didn't last long. In 1989, the boys renamed themselves Green Day, which was also the title of a little ditty they had written about one of their favorite pastimes: hanging out and smoking pot. The Green Day lineup was rounded out by a drummer named John Kiftmeyer, a.k.a. Al Sobrante. Knowing that Lookout Records was the label to be on if you were a self-respecting Bay area punk band, the members of the newly-baptized Green Day pestered Livermore about signing them. He eventually agreed to give them a listen on the condition that they drive up to Mendocino County and play. The band members arranged a venue for the gig, but when they arrived, they discovered that they had booked an empty house with no electricity. Taking pity on them, Livermore rigged up a generator so that Green Day could play; he was so impressed with the performance the band gave in the little room before a crowd of twelve candle-holding people that he signed them on the spot. Later that same year, 1989, the band released a first EP, 1,000 Hours, the inaugural effort was followed with the 1990 album 39/Smooth, which cost $600 to record.
Kiftmeyer decided to leave the band following the release of 39/Smooth to attend college, and was soon replaced by Tre Cool, whom the band had met at Gilman Street. Revved up and ready to hit the road with its new lineup, Green Day kicked off a national tour the day after Dirnt graduated from high school, in 1990 (Armstrong and Cool had previously dropped out of school). After months of touring and playing skateparks and VFW halls, the band headed back into the studio. Green Day's second album, 1992's Kerplunk, was recorded in five days on a $1,000 budget.
By the time Kerplunk had dropped into record-store bins, word had already gotten around about the exciting new punk trio, and both its albums sold in excess of 30,000 copies to break all of Lookout's previous sales records. Unlike most indie bands, Green Day really covered some ground, completing five American tours (one of which was with Bad Religion) and two European tours. On their American treks, the band members traveled in a most unlikely tour bus: an old bookmobile that Cool's dad bought from a library and outfitted with bunks and equipment-storage areas; Mr. Wright also served as the bookmobile driver.