Black Sabbath’s debut album is the birth of heavy metal as we now know it. Compatriots like Blue Cheer, Led Zeppelin, and Deep Purple were already setting new standards for volume and heaviness in the realms of psychedelia, blues-rock, and prog rock. Yet of these metal pioneers, Sabbath are the only one whose sound today remains instantly recognizable as heavy metal, even after decades of evolution in the genre.

-AllMusic Review by Steve Huey-