13There's a lot of pressure involved with being the rulers of the underworld, and nobody knows it better than Black Sabbath in 2013. Inarguable legends and at least partially responsible for creating heavy metal as we know it with their classic '70s material, Sabbath have spawned generations of followers and become one of the final words of the genre. There have been countless reunions and mutations of the band following vocalist Ozzy Osbourne's first