Frequently bootlegged and now digitally remastered by Jimmy Page, these tapes capture a 25-month (1969 to 1971) arc in which Zep's sound grew to encompass the speed rush and jazz/blues festival stuff of their 1969 debut, the fully developed folkie musings of "Going to California" (in which Plant vowed to make a hejira right up to Joni Mitchell's front door), and the band's modestly popular multilayered epic "Stairway to Heaven." The Sessions also give a glimpse of nearly off-the-cuff invention in an intense take on Robert Johnson's "Traveling Riverside Blues". Most other white blues musicians would've rushed to get this on vinyl; Page and Plant instead used it for parts, most notably taking its profound acoustic freneticism for Led Zeppelin III. --Rickey Wright