Would there be heavy metal without Black Sabbath? Possibly. But it wouldn’t sound nearly as menacing or as dark (or as awesome) if Black Sabbath didn’t set the template in the early ‘70s. Starting with their self-titled debut album in 1970, and running all the way up through 2013’s reunion LP with singer Ozzy Osbourne, the quartet has shaped and defined the way heavy music has sounded and has been played for more than 40 years. From Osbourne’s prince-of-darkness wail and Tony Iommi’s sludgy guitar riffing to Geezer Butler’s crawling bass lines and Bill Ward’s deathly drum smacks, Black Sabbath’s music has influenced generations of hard-rock, stoner-rock and heavy-metal artists. Personnel changes over the years (including various singers who followed Osbourne’s initial successor Ronnie James Dio) somewhat softened their bite, but there’s no getting around the sheer force that drives the group’s classic records.