AC/DC are an Australian rock band formed in Sydney in 1973 by brothers Malcolm and Angus Young. Although the band are commonly classified as hard rock, and considered pioneers of heavy metal, they have always classified their music as "rock and roll".
AC/DC underwent several line-up changes before releasing their first album, High Voltage, in 1975. Membership remained stable until bassist Mark Evans was replaced by Cliff Williams in 1977. In 1979, the band recorded their highly successful album Highway to Hell. Lead singer and co-songwriter Bon Scott died on 19 February 1980, after a night of heavy alcohol consumption. The group briefly considered disbanding, but soon ex-Geordie singer Brian Johnson was selected as Scott's replacement. Later that year, the band released their best-selling album, Back in Black.
The band's next album, For Those About to Rock We Salute You, was also highly successful and was their first album to reach number one in the United States. AC/DC declined in popularity soon after drummer Phil Rudd was fired in 1983 and replaced by future Dio drummer Simon Wright. Poor record sales continued until the release of The Razors Edge in 1990, the only studio album to feature Wright's replacement Chris Slade. Phil Rudd returned in 1994 (after Slade was asked to leave in favour of him) and contributed to the band's 1995 album Ballbreaker. Stiff Upper Lip was released in 2000 and was well-received by critics. The band's most recent album Black Ice was released on 20 October 2008.
AC/DC has sold more than 200 million albums worldwide, including 71 million albums in the United States. Back in Black has sold an estimated 42 million units worldwide and 22 million in the United States alone, where it is the fifth highest-selling album. AC/DC ranked fourth on VH1's list of the "100 Greatest Artists of Hard Rock" and the seventh "Greatest Heavy Metal Band Of All Time" by MTV. In 2004, the band was ranked number 72 in the Rolling Stone list of the 100 Greatest Artists of All Time.