Black Sabbath was a rock band.
Black Sabbath were an English rock band , formed in Birmingham in 1968 , by guitarist and main songwriter Tony Iommi , bassist and main lyricist Geezer Butler , singer Ozzy Osbourne , and drummer Bill Ward . 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 . Black Sabbath are often cited as pioneers of heavy metal music . The band helped define the genre with releases such as Black Sabbath ( 1970 ) , Paranoid ( 1970 ) and Master of Reality ( 1971 ) .