20 Most IMPORTANT Classic Rock Albums Ever Made

The Yardbirds were one of the more adventurous acts of the 1960's. Originally a blues band, their experimentation with off-the-wall arrangements and psychedelic sounds was a gamechanger at the end of the decade. As time went on though, guitarist Jimmy Page had plans for something even more ambitious.

Forming Led Zeppelin in the late 60's, the band were one of the finest rock bands in existence, as they took the blues rock of earlier bands and invented the hard rock riff as we know it today. Though Zeppelin fans have contested for decades as to which album is the best, their fourth untitled offering is the closest they have to come to rock perfection. Instead of relying on blues as a crutch, this is the sound of four musicians who are free to toy with the boundaries of the rock format, going from raucous rockabilly on "Rock and Roll" to the colossal "Stairway to Heaven," each of which show Robert Plant's gutteral wail and the pure muscle behind John Bonham's drum kit.

To make sure you're still on familiar ground, the closer "When the Levee Breaks" takes us back to the blues...that happens to be taking place during the rapture. It's debatable whether this album is the best record ever made, but when you think of everything a good rock record should have, 90% of fans end up describing an album like this.