AC/DC are an Australian hard rock band formed in Sydney, Australia in 1973 by brothers Angus and Malcolm Young. Although the band are considered pioneers of heavy metal, its members have always classified their music as "rock 'n' roll".

AC/DC underwent several line-up changes before releasing their first album, High Voltage, in 1975. Membership remained stable until bassist Cliff Williams replaced Mark Evans 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 the departure of drummer Phil Rudd in 1983. Poor record sales continued until the release of The Razors Edge in 1990. Phil Rudd returned in 1994 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 new album Black Ice was announced in June 2008 and is set for release on 20 October 2008.
 
AC/DC have sold more than 200 million albums worldwide,  including 69 million albums in the US.  Back in Black has sold an estimated 42 million units worldwide and 22 million in the US alone,  making it the fifth highest-selling album ever in the US. 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.

Angus and Malcolm Young developed the idea for the band's name after seeing the acronym "AC/DC" on the back of a sewing machine owned by their older sister, Margaret Young. "AC/DC" is an abbreviation for "alternating current/direct current", which indicates that the electricity is being converted from alternating current (wall outlet) to direct current (sewing machine). The brothers felt that this name symbolised the band's raw energy, power-driven performances, and a love for their music.  "AC/DC" is pronounced one letter at a time, though the band is popularly known as "Acca Dacca" in Australia.

Brothers Angus, Malcolm, and George Young were born in Glasgow, Scotland, and moved to Sydney, Australia with most of their family in 1963. George was the first to learn to play the guitar. He became a member of The Easybeats, Australia's most successful band of the 1960s. In 1966, they became the first local rock act to have an international hit, with the song "Friday on My Mind".  Malcolm followed in George's footsteps by playing with a Newcastle, New South Wales band called The Velvet Underground (not to be confused with the New York-based The Velvet Underground).

In November 1973, Malcolm and Angus Young formed AC/DC and recruited bassist Larry Van Kriedt, vocalist Dave Evans, and Colin Burgess, ex-The Masters Apprentices drummer. The band played their first gig at a club named Chequers in Sydney on New Year's Eve, 1973.  They were later signed to the EMI-distributed Albert Productions label for Australia and New Zealand. The early line-up of the band changed often; Colin Burgess was the first member fired, and several bassists and drummers passed through the band during the next year.

By this time, Angus Young had adopted his characteristic school uniform stage outfit. The original uniform was reputedly from his secondary school, Ashfield Boys High School in Sydney; the idea was his sister Margaret's. Angus had tried other costumes, such as Spider-Man, Zorro, a gorilla, and a parody of Superman, named Super-Ang.  In fact in its early days, most members of the band dressed in some form of glam or satin outfit but this approach was abandoned when it was discovered Melbourne band Skyhooks had already adopted this approach to their stage presentation.

The Young brothers decided that Evans was not a suitable frontman for the group, because they felt he was more of a glam rocker like Gary Glitter.  On stage, Evans was occasionally replaced by the band's first manager, Dennis Laughlin, who was the original lead singer with Sherbet prior to Daryl Braithwaite joining the band. Evans had interpersonal problems with Laughlin, which also contributed to the band's ill feeling toward Evans.  Meanwhile Ronald Belford "Bon" Scott, an experienced vocalist and friend of George Young's, was interested in becoming their vocalist.

In September 1974, Bon Scott replaced Dave Evans. The band had recorded only one single with Evans, "Can I Sit Next to You" / "Rockin' in the Parlour", and "Can I Sit Next to You" was eventually re-recorded with Bon Scott under the title "Can I Sit Next to You Girl".

Between 1974 and 1977, aided by regular appearances on Molly Meldrum's Countdown, a nationally broadcast pop music television show, AC/DC became one of the most popular and successful acts in Australia. Their performance on 3 April 1977 was their last live TV appearance for over twenty years.

In 1976, the band signed an international deal with Atlantic Records, and toured extensively throughout Europe. They gained invaluable experience of the stadium circuit, supporting leading hard rock acts such as Aerosmith, Kiss, Styx and Blue Öyster Cult, and co-headlined with Cheap Trick.

The first AC/DC album to gain worldwide distribution was a 1976 compilation of tracks taken from the High Voltage and T.N.T. LPs. Also titled High Voltage, and released on the Atlantic Records label, the album sold three million copies worldwide, partly due to its popularity with a British punk audience.  The track selection was heavily weighted toward the more recent T.N.T., and included only two songs from their first LP. The band's next album, Dirty Deeds Done Dirt Cheap, was released in the same year in both Australian-only and international versions, like its predecessor. Track listings varied worldwide, and the international version of the album also featured "Rocker" from T.N.T. The original Australian version included "Jailbreak" (now more readily available on the 1984 compilation EP '74 Jailbreak or as a live version on the 1992 Live album). Dirty Deeds was not released in the US until 1981, by which time the band were at the peak of their popularity.

Following the 1977 recording Let There Be Rock, bassist Mark Evans was sacked due to personal differences with Angus Young. He was replaced by Cliff Williams, who also provided backing vocals alongside Malcolm Young. Neither of the Young brothers has elaborated on the departure of Evans, though Richard Griffiths, the CEO of Epic Records and a booking agent for AC/DC in the mid-1970s, later commented, "You knew Mark wasn't going to last, he was just too much of a nice guy."
 
AC/DC's first American exposure was through the Michigan radio station AM 600 WTAC in 1977. The station's manager, Peter C. Cavanaugh, booked the band to play at Flint's Capitol Theater. The supporting act was MC5, who had just briefly reunited and agreed to play at the event. The band opened with their popular song "Live Wire" and closed with "It's a Long Way to the Top (If You Wanna Rock 'n' Roll)".

The band's sixth album, Highway to Hell, was produced by Robert Lange and released in 1979. It became the first AC/DC LP to break into the US top 100, eventually reaching #17, and it propelled AC/DC into the top ranks of hard rock acts. Highway to Hell put increased emphasis on backing vocals but still featured AC/DC's signature sound: loud, simple, pounding riffs and grooving backbeats.  The final track, "Night Prowler", has two breaths in quick succession at the start of the song, intended to create a tone of fear and loathing.
 
In 1986, the group returned to the charts with the made-for-radio "Who Made Who". The album Who Made Who was the soundtrack to Stephen King's film Maximum Overdrive, and is the closest the band has come to releasing a "greatest hits" collection, which AC/DC have always refused to do.  It brought together older hits, such as "You Shook Me All Night Long" and "Ride On", with newer songs such as title track "Who Made Who", and two new instrumentals, "D.T." and "Chase the Ace".

In February 1988, AC/DC were inducted into the Australian Recording Industry Association's Hall of Fame.

AC/DC's 1988 album, Blow Up Your Video, was recorded at Miraval Studio in Le Val, France, and reunited the band with their original producers, Harry Vanda and George Young. The group recorded nineteen songs, choosing ten for the final release; though the album was later criticised for containing excessive "filler", it was a commercial success. Blow Up Your Video sold more copies than the previous two studio releases combined, and reached #2 on the UK charts—AC/DC's highest position since Back in Black in 1980. The album featured the UK top-twenty single "Heatseeker", and popular songs such as "That's the Way I Wanna Rock and Roll". The Blow Up Your Video World Tour began in February 1988, in Perth, Australia. That April, following live appearances across Europe, Malcolm Young announced that he was taking time off from touring, principally to begin recovery from his alcoholism. Another member of the Young family, Stevie Young, temporarily took Malcolm's place.

In 1997, a box set named Bonfire was released. It contained four albums; a remastered version of Back in Black; Volts (a disc with alternate takes, outtakes, and stray live cuts) and two live albums, Live from the Atlantic Studios and Let There Be Rock: The Movie. Live from the Atlantic Studios was recorded in 1978 at the Atlantic Studios in New York. Let There Be Rock: The Movie was a double album recorded in 1979 at The Pavillon in Paris, and was the soundtrack of a motion picture, AC/DC: Let There Be Rock. The US version of the box set included a colour booklet, a two-sided poster, a sticker, a temporary tattoo, a keychain bottle opener, and a guitar pick.
 
In 2000, the band released their fourteenth studio album, Stiff Upper Lip, produced by George Young. The album was better received by critics than Ballbreaker, but was considered lacking in new ideas.  The Australian release included a bonus disc with three promotional videos and several live performances recorded in Madrid in 1996. Stiff Upper Lip reached #1 in five countries, including Argentina and Germany; #2 in three countries, Spain, France and Switzerland; #3 in Australia; #5 in Canada and Portugal; and #7 in Norway, the US and Hungary. The first single, "Stiff Upper Lip", remained at #1 on the US Mainstream Rock charts for four weeks.  The other singles released also did very well; "Safe in New York City" and "Satellite Blues" reached #31 and #7 on Billboard's Mainstream Rock Tracks, respectively.

In 2002, AC/DC signed a long-term, multi-album deal with Sony Music, who went on to release a series of remastered albums as part of their AC/DC remasters series. Each release contained an expanded booklet, featuring rare photographs, memorabilia, and notes.  In 2003, the entire back-catalogue (except Ballbreaker and Stiff Upper Lip) was remastered and re-released. Ballbreaker was eventually re-released in October 2005; Stiff Upper Lip was later rereleased in April 2007.

On 30 July 2003 the band performed with The Rolling Stones and Rush at Molson Canadian Rocks for Toronto. The concert, held before an audience of half a million, was intended to help the city overcome the negative publicity stemming from the effects of a 2003 severe acute respiratory syndrome epidemic. The concert holds the record for the largest paid music event in North American history. The band came second in a list of Australia's highest-earning entertainers for 2005, and sixth for 2006, despite having neither toured since 2003 nor released an album since 2000. Verizon Wireless has gained the rights to release AC/DC's full albums and the entire Live at Donington concert to download in 2008.

On 16 October 2007, Columbia Records released a double and triple DVD titled Plug Me In. The set consists of 5 and 7 hours of rare footage, and even a recording of AC/DC at a high school performing "School Days", "T.N.T.", "She's Got Balls", and "It's a Long Way to the Top (If You Wanna Rock 'n' Roll)". As with Family Jewels, disc one contains rare shows of the band with Bon Scott, and disc two is about the Brian Johnson era. The collector's edition contains an extra DVD with 21 more rare performances of both Scott and Johnson and more interviews.

AC/DC made their video game debut on Rock Band 2, with "Let There Be Rock" included as a playable track.  It is also heavily rumored that the entirety of Live at Donington will be released as additional downloadable content to the game on October 16, 2008.

On September 15, 2008, AC/DC Radio will debut on Sirius channel 29 and XM channel 53 . The exclusive 24/7, limited engagement channel will play classics like “You Shook Me All Night Long” and “Back in Black,” preview tracks from their upcoming release, Black Ice, and feature exclusive interviews with the band members who share their personal insights into their music and their career spanning more than 30 years.
 
On 18 August 2008, Columbia Records announced the 18 October Australian release, and 20 October for the rest of the world to release of AC/DC's sixteenth studio album Black Ice. It will be the band's first studio album in eight years. Black Ice features 15 new tracks from brothers Angus and Malcolm Young, Brian Johnson, Cliff Williams, and Phil Rudd. The album was produced by Brendan O'Brien and recorded at the Warehouse Studio in Vancouver, Canada.

"Rock 'n' Roll Train," the album's first single, was released on 28 August. On 15 August, AC/DC recorded a video for a song from the new album in London with a special selection of fans getting the chance to be in the video.  The video was premiered on AC/DC.com on September 18th. AC/DC are set to kick off their first world tour since 2001 in late October. The new single has also now been set as the background music to the band's website.

Black Ice will be sold in the US exclusively at Wal-Mart and Sam's Club and the band's official website.

An 18 month world tour supporting the new album was announced on September 11 and will begin on October 28 in Wilkes-Barre, PA.. They have announced 26 dates in North America between October and December, and it is expected that the second leg of the tour will commence in the new year. Dates for South America, Australia, Europe and Asia are expected to be announced later this year.