Black Sabbath are an English heavy metal band from Birmingham, England. Formed in 1968 by Ozzy Osbourne (lead vocals), Tony Iommi (guitar), Geezer Butler (bass), and Bill Ward (drums and percussion), the band has since experienced multiple lineup changes, with a total of twenty-two former members. Originally formed as a heavy blues-rock band named Earth, the band began incorporating occult- and horror-inspired lyrics with tuned-down guitars, changing their name to Black Sabbath and releasing multiple gold and platinum records in the 1970s.

As one of the most influential heavy metal bands of all time, Black Sabbath helped define the genre with releases such as 1970's quadruple-platinum Paranoid. Black Sabbath has sold more than 100 million albums worldwide, and were ranked number one on MTV's Greatest Metal Bands countdown. Ozzy Osbourne was fired from the band in 1979, and while initially replaced by former Rainbow vocalist Ronnie James Dio, Black Sabbath would see a revolving lineup in the 1980s and 1990s that included vocalists Ian Gillan, Glenn Hughes, Ray Gillen and Tony Martin. The original lineup reunited with Osbourne in 1997 and released a live album, Reunion, which spawned the Grammy Award-winning single "Iron Man" in 2000, thirty years after the song's initial release on Paranoid.

Currently, the early 1980s line-up featuring Iommi, Butler, Dio, and Vinny Appice are recording a new album under the moniker Heaven and Hell, a title taken from the 1980 Black Sabbath song and album of the same name.

Formation and early days (1968–1969)

Following the breakup of their previous band Mythology in 1968, guitarist Tony Iommi and drummer Bill Ward sought to form a heavy blues band in Aston, Birmingham, England. The group enlisted bassist Geezer Butler, and vocalist Ozzy Osbourne, who had played together in a band called Rare Breed. The new group was initially named The Polka Tulk Blues Company, and also featured slide guitarist Jimmy Phillips and saxophonist Alan "Aker" Clarke. After shortening the name to Polka Tulk, the band changed their name to Earth, and continued as a four-piece without Phillips and Clarke.

Earth played club shows in England, Denmark, and Germany, with sets consisting of cover songs by Jimi Hendrix, Blue Cheer, and Cream; as well as lengthy improvised blues jams. In December 1968, Tony Iommi abruptly left Earth to join Jethro Tull. Although his stint with the band would be short-lived, Iommi made an appearance with Jethro Tull on the The Rolling Stones Rock and Roll Circus TV show. Unsatisfied with the direction of Jethro Tull, Iommi returned to Earth in January 1969. "It just wasn't right, so I left", Iommi said. "At first I thought Tull were great, but I didn't much go for having a leader in the band, which was Ian Anderson's way. When I came back from Tull, I came back with a new attitude altogether. They taught me that to get on you got to work for it".