Led Zeppelin

Led Zeppelin formed from the end of the Yardbirds and immediately made blues rock feel huge. Jimmy Page’s production, Robert Plant’s high vocals, John Paul Jones’s arrangements and John Bonham’s drums turned blues forms, folk echoes and riff-based writing into a sound built for large rooms.

They are central to hard rock because they made heaviness flexible: acoustic and electric, borrowed and invented, precise and excessive at once. The later heavy metal branch inherits much of its grammar from this node.