When guitarist Dave Mustaine was booted out of Metallica early in its career, he formed Megadeth, which continued his former group’s thrash-metal style with even more speed and intensity.

Mustaine was seven when his parents divorced, and his family wound up living in poverty in the Southern California suburbs. During his teens, Mustaine’s mother was often away, leaving him with his sisters; he told a journalist that a brother-in-law once punched him in the face for listening to Judas Priest. Mustaine’s revenge was to join a heavy-metal band, and in 1981 he became a founding member of Metallica [see entry], from which he was fired two years later in a power struggle over leadership and allegations of his drug use. Mustaine, whose reputation for outspokenness and mood swings is notorious, formed Megadeth that same year with Minnesota native Dave Ellefson.

Mustaine and Ellefson hoped to create a jazz-oriented progressive strain of heavy metal based on chops as much as emotional aggression. Megadeth’s first album, Killing Is My Business…and Business Is Good, succeeded in that regard and garnered mainly positive reviews, even from critics normally hostile to heavy metal. Mustaine’s drug use, meanwhile, deepened with his discovery of heroin. Still, the band’s subsequent albums, Peace Sells…But Who’s Buying? (#76, 1986) and So Far, So Good…So What? (#28, 1988), continued in its celebrated lightening-speed chops-heavy style.

In 1990 Mustaine was arrested for impaired driving and went into a 12-step program for his drug and alcohol problems. The same year, Megadeth released Rust in Peace, which reached #23. Mustaine’s former band, meanwhile, paved the way for thrash metal when its self-titled album of 1991 skyrocketed to the top of the charts; Megadeth followed in Metallica’s footsteps the next year with Countdown to Extinction, which went to #2.

Offstage, Mustaine continued getting into trouble: In 1993, Megadeth was dumped from its opening spot on Aerosmith’s tour when that group tired of Mustaine’s misbehavior. Megadeth returned in 1994 with Youthanasia (the album’s press release was written by novelist Dean Koontz), which debuted at #4. That same year, Mustaine slipped back into drug use briefly during a tour, but has since returned to sobriety, claiming even to refuse nitrous oxide while in the dentist’s chair.

Before recording 1997’s Cryptic Writings (#10), Mustaine started work on a degree in business management at the University of Phoenix and began mastering Web design. He put those new skills to work when his company designed the Web site for Alice Cooper’s theme restaurant, Alice Cooper’stown.

Megadeth’s lineup changes continued, as former Suicidal Tendencies drummer Jimmy DeGrasso joined in time for 1999’s Risk. That album’s title and revamped sound were inspired by published comments from Metallica’s Lars Ulrich suggesting that Megadeth take more musical risks. The subsequent album incorporated surprising industrial and Middle Eastern flavors along the edges.