Premise: 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 . 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 . They have also won two Grammy Awards for Best Metal Performance .
Hypothesis: Black Sabbath was only a jazz band.
Label: CONTRADICTION