Encompassing heavy metal, folk, pure rock & roll, and blues, Led Zeppelin's untitled fourth album is a monolithic record, defining not only Led Zeppelin but the sound and style of '70s hard rock. Expanding on the breakthroughs of III, Zeppelin fuse their majestic hard rock with a mystical, rural English folk that gives the record an epic scope. Even at its most basic -- the muscular, traditionalist "Rock and Roll" -- the album has a grand sense of drama, which is only deepened by Robert Plant's burgeoning obsession with mythology, religion, and the occult. Plant's mysticism comes to a head on the eerie folk ballad "The Battle of Evermore," a mandolin-driven song with haunting vocals from Sandy Denny, and on the epic "Stairway to Heaven." Of all of Zeppelin's songs, "Stairway to Heaven" is the most famous, and not unjustly. Building from a simple fingerpicked acoustic guitar to a storming torrent of guitar riffs and solos, it encapsulates the entire album in one song. Which, of course, isn't discounting the rest of the album. "Going to California" is the group's best folk song, and the rockers are endlessly inventive, whether it's the complex, multi-layered "Black Dog," the pounding hippie satire "Misty Mountain Hop," or the funky riffs of "Four Sticks." But the closer, "When the Levee Breaks," is the one song truly equal to "Stairway," helping give IV the feeling of an epic. An apocalyptic slice of urban blues, "When the Levee Breaks" is as forceful and frightening as Zeppelin ever got, and its seismic rhythms and layered dynamics illustrate why none of their imitators could ever equal them.
[Led Zeppelin launched a massive, Jimmy Page-supervised reissue campaign in 2014, where each of their studio albums was remastered and then expanded with a bonus disc of alternate versions (in the case of the super deluxe editions, they were also supplemented by vinyl pressings and a massive hardcover book). The supplemental disc for Led Zeppelin IV is constructed as a mirror image of the finished album, comprised almost entirely of alternate mixes and instrumentals. "The Battle of Evermore" and "Going to California" belong to the latter category, consisting of nothing but the acoustic guitar and mandolin parts from the finished track, while the rest of the record is devoted to alternate mixes from various sources. Occasionally, a distinction leaps out -- there's a notable lack of swampy, cavernous echo on "When the Levee Breaks," perhaps a few more keyboards on the midsection of "Stairway to Heaven" -- but generally these mixes are leaner, tighter, and not all that different from the finished version. A song or two feels slightly different -- "Misty Mountain Hop" jumps a bit as it seems to groove a little bit stronger -- but by and large this disc shows that as a producer, Page not only knew where he wanted to go but he knew how to get it right the first time.]