Black Sabbath was formed in Birmingham, England in 1968, by guitarist and main songwriter Tony Iommi, bassist and main lyricist Geezer Butler, singer Ozzy Osbourne, and drummer Bill Ward. The band have since experienced multiple line-up changes, with guitarist Iommi being the only constant presence in the band through the years. Originally formed as a blues rock band, the group soon adopted the Black Sabbath moniker and began incorporating occult themes with horror-inspired lyrics and tuned-down guitars. Despite an association with these two themes, they also composed songs dealing with social instability, political corruption, the dangers of drug abuse and apocalyptic prophecies of the horrors of war. Osbourne’s regular abuse of drugs and alcohol led to his dismissal from the band in 1979. He was replaced by former Rainbow vocalist Ronnie James Dio. The original line-up reunited with Osbourne in 1997 and released a live album, Reunion. Black Sabbath’s 19th studio album, 13, which features all of the original members but Ward, was released in June 2013. Black Sabbath are often cited as pioneers of heavy metal music and have sold over 70 million records worldwide.