AC/DC are an Australian rock band, formed in 1973 by brothers Malcolm and Angus Young, who have remained the sole constant members. Commonly classified as hard rock, they are considered pioneers of heavy metal and are sometimes classified as such, though they themselves have always classified their music as simply "rock and roll". To date they are one of the highest grossing bands of all time.
AC/DC underwent several line-up changes before releasing their first album, High Voltage, on 17 February 1975. Membership subsequently stabilised until bassist Mark Evans was replaced by Cliff Williams in 1977 for the album Powerage. Within months of recording the 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 Scott's parents urged them to continue and hire a new vocalist. Ex-Geordie singer Brian Johnson was auditioned and selected to replace Scott. Later that year, the band released their highest selling album, and ultimately the second highest-selling album by any artist, Back in Black.
The band's next album, For Those About to Rock We Salute You, 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 was replaced by future Dio drummer Simon Wright. The band experienced a resurgence in the early 1990s with the release of The Razors Edge. Phil Rudd returned in 1994 (after Chris Slade, who was with the band from 1989–1994, was asked to leave in favour of him) and contributed to the band's 1995 album Ballbreaker. Since then, the band's line-up has remained the same. Stiff Upper Lip was released in 2000 and was well received by critics, and the band's latest studio album, Black Ice, was released on 20 October 2008. It was their biggest hit on the charts since For Those About to Rock, eventually reaching No.1 on all of them.
As of 2010, AC/DC had sold more than 200 million albums worldwide, including 71 million albums in the United States alone. Back in Black has sold an estimated 50 million units worldwide, making it the second highest-selling album by any artist - behind only Michael Jackson's Thriller - and the highest-selling album by any band. The album has sold 22 million units in the U.S. alone, where it is the sixth highest-selling album of all-time. AC/DC ranked fourth on VH1's list of the "100 Greatest Artists of Hard Rock" and were named the seventh "Greatest Heavy Metal Band of All Time" by MTV. In 2004, AC/DC were ranked number 72 in the Rolling Stone list of the "100 Greatest Artists of All Time". In 2010, AC/DC were ranked number 23 in the VH1 list of the "100 Greatest Artists of All Time".