Black Sabbath are an English heavy metal band, formed in Aston, Birmingham in 1969 by Ozzy Osbourne (lead vocals), Tony Iommi (guitar), Geezer Butler (bass guitar), and Bill Ward (drums). The band has since experienced multiple line-up changes, with Tony Iommi the only constant presence in the band through the years. A total of 22 musicians have at one time been members of Black Sabbath. Originally formed in 1968 as a heavy blues rock band named Earth and renamed to Black Sabbath in 1969, the band began incorporating occult- and horror-inspired lyrics with tuned-down guitars and achieving multiple platinum records in the 1970s. Despite an association with occult and horror themes, Black Sabbath also composed songs dealing with social instability, political corruption, the dangers of drug abuse and the often apocalyptic prophesies of the horrors of war. Black Sabbath are cited, along with Led Zeppelin and Deep Purple, as pioneers of heavy metal. The band helped define the genre with releases such as quadruple-platinum Paranoid, released in 1970. They were ranked by MTV as the "Greatest Metal Band" of all time, and placed second in VH1's "100 Greatest Artists of Hard Rock" list, behind Led Zeppelin. Rolling Stone has posited the band as 'the heavy-metal kings of the '70s'. They have sold over 15 million records in the United States alone and more than 70 million records worldwide. Black Sabbath were inducted into the Rock and Roll Hall of Fame in 2006, and were included among Rolling Stone's list of the 100 Greatest Artists of All Time.