Few bands can claim to have invented an entire genre of music. The Beatles didn’t do it. The Beach Boys and visionary writer and producer Brian Wilson didn’t do it. Frank Zappa didn’t do it. Black Sabbath, a band once filleted by rock critics like Lester Bangs and targeted by generations of parents for allegedly ruining their children’s lives, did. In the course of their long career (44 years and counting), Black Sabbath altered the sound of music, became a cornerstone for every teenager who didn’t fit in and, in the process, redefined what was possible in rock.