Megadeth is an American thrash metal band led by founder, frontman, guitarist, and songwriter Dave Mustaine. Formed in 1983 Los Angeles, California with bass player Dave Ellefson following Mustaine's departure from Metallica, the band has since released twelve studio albums, six live albums, two EPs, thirty singles, thirty-two music videos, and three compilations. As a pioneer of the American thrash metal movement, Megadeth rose to international fame in the 1980s, but experienced numerous line-up changes, due partly to the band's notorious substance abuse problems.