What else would I be listening to on this unholiest of days? (I bought this original German Vertigo pressing a decade ago for 10 bucks, for you nerds). Released in the UK on February 13, 1970–Friday the 13th, of course–Black Sabbath’s debut invented an entire genre–guess which one? Fifty years ago. There were a lot of hard rock bands at the time (Sir Lord Baltimore, Coven, Blue Cheer), but no one conjured the bleakness or evil that these four blokes from Birmingham had. Or the riffs. Or that voice. Tony Iommi rightfully gets credit for creating some of the most menacing riffs ever put on tape, but Ozzy Osbourne’s vocals were from another dimension. Add to that a rhythm section of bassist Geezer Butler and drummer Bill Ward, and you have a band that would release six straight untouchable records that can still crush anything that has come since. Heavy metal as we know it started right here. Let us pray. And let us listen to my favorite cut from this slab o’ doom.