"As the late 1960s bled into the early 1970s, the Age of Aquarius was under attack from cantankerous and extremely loud sonic forces. The bubbly psychedelia and sweet-tempered music that had fueled hippie hearts and minds were being assailed by steelier and more squalid rock, and many of those rough-necked, hairy harbingers of menace would inspire heavy metal’s ascendence. The debate about who was the first proto-metal artist is an endless circle of arguments and counter-arguments. You can reach back to the 1950s and find heavy metal’s origins in Willie Johnson’s blues, and Link Wray’s guitar rumbles. [...] Ultimately, you can throw everyone who was amplifying their sound and vision in the late 1960s and early 1970s into the gene pool that evolved into heavy metal."