February 13, 1970 – Friday the 13th. In the fog-choked streets of Birmingham, Black Sabbath released their self-titled debut on Vertigo Records. Recorded in just two days at Regent Sound Studios, this album didn’t arrive with fanfare or radio play. It cracked open like a thunderclap in the musical earth: doom-laden riffs, occult shadows, rainstorms in the intro, tritones that evoked ancient dread, and a sound so slow, heavy, and ominous that nothing like it had ever reached mainstream ears before. This wasn’t rock anymore. This was the birth cry of heavy metal.