When did heavy metal music emerge as a genre?
Heavy metal music emerged as a genre in 1968 when three bands emerged from the British and American underground to forge a sound that would redefine the limits of volume and distortion. Led Zeppelin, Black Sabbath, and Deep Purple formed that year, creating a thick, monumental sonic architecture built on the back of blues rock, psychedelic rock, and acid rock. The 1970 releases by Black Sabbath, including the album Paranoid, and Deep Purple's Deep Purple in Rock, were crucial in codifying the genre.