Sound — 10
The sound on this album is proof that Led Zeppelin is not only the greatest heavy band of all time, but that they were the only band to really ever understand the concept of heavy music. Led Zeppelin shows hear on songs like "When The Levee Breaks" and "Stairway to Heaven" that the heaviness of a song comes from the energy generated by the song, not how loud it is. When the energy peaks at the chorus of "When the Levee Breaks" and then drops back into a riff with a reversed harmonica that sounds like one of the battle horns in "Lord of the Rings", one can't help but laugh at how hopelessly pathetic every other metal/emo bands concept of heavy music is. Equally impressive as the heaviness of the music is the variety on this album. Every song is completley different than the others, with sounds ranging from straight Zeppelin metal(Black Dog), to an acoustic piece that conveys the sound of 1800s california frontier travel(Going to California). The influence of this album is incalculable, Stairway to Heaven redefined what a rock song was and showed that it didn't have to be constant loud drums and guitar distortion to be rock, though no one has still really been able to grasp that concept even 30 years later. When the levee breaks was recorded in a long stairway to acheive maximum reverb/echo on the drums, and that drum beat is one of the most famous of all time.
Lyrics — 10
The lyrics are absolutely masterful, Plant touches the poetic level of Morrison and Dylan on Stairway to Heaven, and the more rocking pieces like Black Dog have perfect sex-ridden lyrics to complement the sound of the band. Plants singing is superb and is easily his best of all time on When the Levee Breaks, also he is able to easily hold up singing al coppelo on Black Dog, a testament to his skill as a singer.
Overall Impression — 10
Everyone has their favorite Zeppelin album so it's hard to say if this is the best, it certainly contains their greatest acheivements "Stairway to Heaven and When the Levee Breaks", and is certainly the greatest variety of sound on any of their albums. I still listen to some of these songs everyday, I would buy it for sure if I lost it. The best thing about the album is that it's a rock band who knows their making some of the greatest rock music of all time, but they deliver it in such a way that the music still comes off as being purely for the audience, purely for your own listening pleasure, and even some hope for those with lives full of trouble and trauma, and not at all self-indulgent like their contemporaries Van Halen and Metallica. It is, in every sense of the word "art" while still being just great party/dance/good time rock and roll.