The archetypal heavy metal band, Black Sabbath unleashed a debut album marked by ponderous, sludgy rhythms, heavily distorted riffs and chords, and more than a whiff of darkness and Black Magic. Its crushing atmosphere of doom proved intense and relentless; the cumulative effect was dubbed "downer rock," but it proved immediately popular with a disaffected audience. Though no one could have predicted it at the time, Sabbath was laying the groundwork for a genre that would continue to grow in popularity through the '70s, '80s, '90s, and beyond.