Released on Friday, February 13, 1970, today marks the 45th anniversary of Black Sabbath, the debut album by the legendary band of the same name. In many ways, Black Sabbath — released on a Friday the 13th like today — stands atop a short list of influential albums which nearly singlehandedly ushered in a sound, genre, influence, and style that continues to be studied and copied endlessly by musicians and bands globally.

In Black Sabbath‘s case, they fused together a musical amalgam of Sun Records style rock and roll, doomy blues, classical overtones, jazz complexities, and a drudging sound to create a concoction that had never been heard before it. While many of the most groundbreaking bands in musical history (even The Beatles) sort of wear their influences right on their sleeves (think about Led Zeppelin records), Black Sabbath had a sound, stance, and style that almost was like coming from a mold specifically created for them.