Ozzy Osbourne (vocals), Tony Iommi (guitar), Terry "Geezer" Butler (bass), Bill Ward (drums).

Considered by many to be the first heavy metal band, Black Sabbath was formed in 1968 by Tony Iommi, Ozzy Osbourne, Geezer Butler and Bill Ward. The original line up lasted until 1979, after which Osbourne was fired and replaced by Ronnie James Dio. The line up changes would continue, with no line up remaining intact for consecutive studio releases. Throughout the changes, only Tony Iommi and keyboardist Geoff Nicholls, who also joined the band in 1979, would remain with the band, although Nicholls would not always be credited as a full member. In 1997, Iommi, Butler, Ward, and Osbourne reunited permanently, touring and releasing a live album in 1998, although a long-rumored studio release has yet to appear. Since then, the group has periodically reunited to tour with Ozzy's "Ozzfest" tour. In 2004, longtime keyboardist Geoff Nicholls was replaced by Adam Wakeman for an Ozzfest tour. No reason was given for the replacement. In 2006, the original line up was inducted into the Rock 'n' Roll Hall Of Fame.

In 2007, Tony Iommi, Geezer Butler, Ronnie James Dio, and drummer Vinny Appice (who were featured on 1981's "Mob Rules" and 1992's "Dehumanizer") announced that they would tour together as Heaven & Hell (2) (with Iommi, who owns the Black Sabbath name, deciding to keep the Black Sabbath name solely for the original line up in light of their Rock 'n' Roll HOF induction) to support a Dio-era greatest hits release, which also featured 3 new Dio/Iommi compositions. A live album was also released under the Heaven & Hell name. In late 2007, it was announced that Heaven & Hell were seeking a record deal and planned to record a new album in 2008.