AC/DC are an Australian rock band, formed in 1973 by brothers Malcolm

Malcolm Young

Malcolm Young is a Scottish-born Australian guitarist, best known as a founding member, rhythm guitarist, backing vocalist and songwriter for the Australian hard rock band AC/DC. Young was inducted into the Rock and Roll Hall of Fame in 2003, along with the other members of AC/DC...

 and Angus Young

Angus Young

Angus McKinnon Young is a Scottish-born Australian musician, and the lead guitarist, songwriter, and co-founder of the rock and roll band AC/DC. He was inducted into the Rock and Roll Hall of Fame along with other members of AC/DC in 2003 and is known for his energetic performances,...

. Commonly classified as hard rock

Hard rock

Hard rock is a loosely defined genre of rock music which has its earliest roots in mid-1960s garage rock, blues rock and psychedelic rock...

, they are considered pioneers of heavy metal

Heavy metal music

Heavy metal is a genre of rock music that developed in the late 1960s and early 1970s, largely in the Midlands of the United Kingdom and the United States...

, though they themselves have always classified their music as simply "rock and roll

Rock and roll

Rock and roll is a genre of popular music that originated and evolved in the United States during the late 1940s and early 1950s, primarily from a combination of African American blues, country, jazz, and gospel music...

". 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

High Voltage (1975 album)

High Voltage is the debut studio album by Australian hard rock band AC/DC, released on 17 February 1975. Six of the album's eight songs were written by Angus Young, Malcolm Young, and Bon Scott. "Soul Stripper" was written by Young & Young, and "Baby, Please Don't Go" is a cover version of a Big...

, on 17 February 1975. Membership remained stable until bassist Mark Evans

Mark Evans (musician)

Mark Whitmore Evans is an Australian bass guitarist who was an early member of hard rock band AC/DC from March 1975 to June 1977. His playing featured on their albums T.N.T, High Voltage, Dirty Deeds Done Dirt Cheap, Let There Be Rock and 74 Jailbreak...

 was replaced by Cliff Williams

Cliff Williams

Clifford Williams is an English bassist and backing vocalist, who has been a member of the Australian hard rock band AC/DC since mid-1977. He had started his professional music career in 1967 and was previously in the British groups Home and Bandit. His first studio album with AC/DC was Powerage...

 in 1977 for the album Powerage

Powerage

Powerage is the fifth studio album by Australian hard rock band AC/DC, released in May 1978. It is also AC/DC's fourth international studio album. All songs were written by Angus Young, Malcolm Young and Bon Scott....

.