Led Zeppelin IV

Led Zeppelin's untitled fourth album is the record that settled the argument about them. Across four sides of vinyl the band pulls every thread of its first three records into one statement: the thundering blues-rock riffing of the debut and second album, the acoustic folk experiments of the third, and a new confidence in dynamics and space. Critics then and now describe it as the point where hard rock came of age — the sound of a band at the height of its powers, with a production (recorded live in a country house) that captures Bonham's cavernous drum sound, Jones's agile bass, Page's layered guitars, and Plant's wailing vocals in a way that changed how heavy music was recorded. "Stairway to Heaven," the eight-minute centerpiece, is the song every epic rock anthem since has been measured against, and it is surrounded by material that on most albums would be the highlight: the stop-start swagger of "Black Dog," the joyful rush of "Rock and Roll," the Celtic folk duet "The Battle of Evermore," the haunting "Going to California," and the slow-motion blues avalanche "When the Levee Breaks."

Its signature gesture is refusal to introduce itself: no title, no band name on the cover, just four symbols and a photograph of an old man carrying sticks — a deliberate rebuke to the press the band felt had misjudged them. The knocks against it are mostly a matter of taste and time. Some critics found the mystical, Tolkien-tinged streak pretentious or limiting, and a recurring complaint is that the second half doesn't match the piled-up first side. Today the biggest obstacle is familiarity: the hits have been played to death on classic-rock radio for fifty years, and listeners hearing "Stairway to Heaven" for the thousandth time can struggle to hear what made it revolutionary. The long-running legal fight over the song's famous opening figure has also become part of its story, even though the band prevailed.

Disagreement among critics centers on what the album's true core is — the heavy blues muscle or the acoustic folk mysticism — and on whether the mysticism is its greatest strength or its most indulgent weakness. But the split is over emphasis, not worth: across every era of criticism there is near-unanimous agreement that this is a landmark, one of the best-selling and most influential rock albums ever made, and the definitive statement of 1970s hard rock.