Led Zeppelin’s debut brings blues-rock to its boiling point and then transforms it into whole new forms. The groaning riffs of “Dazed and Confused” lower us into a molten netherworld, while “Communication Breakdown” lunges forward like a switchblade-slashing assailant. “You Shook Me” and “I Can’t Quit You Baby” turn Willie Dixon licks into apocalyptic thunder, but Page and Plant were already outgrowing Chicago blues. With ominous acoustic passages building to a furious, head-banging stomp, “Babe I’m Gonna Leave You” crashes over the listener in a typhoon of primordial rock force.