I think "That's The Way" from this album and "Bron Yr Aur" recorded during these sessions but added to 1975s Physical Graffiti are the most beautifully moving acoustic performances in the history of Zeppelin…and maybe all time.

The eponymous third studio album by the English rock band Led Zeppelin, released on 5 October 1970 by Atlantic Records in the United States and on 23 October 1970 in the United Kingdom. The songs were recorded using The Rolling Stones Mobile Studio, Headley Grange, and Hampshire Island Studios Olympic Studios, London. The album represented a maturing of the band's music towards a greater emphasis on folk and acoustic sounds. This surprised many fans and critics, and upon its release the album received rather indifferent reviews.

Led Zeppelin III is generally praised and acknowledged as representing an important milestone in the band's history, and a turning point in their music. Although acoustic songs had been featured on its predecessors, this album showed that Led Zeppelin were more than just a conventional rock band, and that they could branch out into wider musical territory, like folk. Full article

Stephen Thomas Erlewine @ Allmusic: On their first two albums, Led Zeppelin unleashed a relentless barrage of heavy blues and rockabilly riffs, but Led Zeppelin III provided the band with the necessary room to grow musically. While there are still a handful of metallic rockers, III is built on a folky, acoustic foundation that gives the music extra depth. And even the rockers aren't as straightforward as before: the galloping "Immigrant Song" is powered by Robert Plant's banshee wail, "Celebration Day" turns blues-rock inside out with a warped slide guitar riff, and "Out on the Tiles" lumbers along with a tricky, multi-part riff. Nevertheless, the heart of the album lies on the second side, when the band delve deeply into English folk. "Gallows Pole" updates a traditional tune with a menacing flair, and "Bron-Y-Aur Stomp" is an infectious acoustic romp, while "That's the Way" and "Tangerine" are shimmering songs with graceful country flourishes. The band hasn't left the blues behind, but the twisted bottleneck blues of "Hats off to (Roy) Harper" actually outstrips the epic "Since I've Been Loving You," which is the only time Zeppelin sound a bit set in their ways.