Joni Mitchell Archives, Vol. 3: The Asylum Years (1972-1975) shines a light on a transitional phase in Mitchell's music. Spanning the period during which she released For the Roses, Court and Spark, and the truly groundbreaking The Hissing of Summer Lawns, it is, in many ways, the most vital and interesting of the three collections so far. (Read our reviews of Vol. 1 and Vol. 2.)

The first two Archives sets charted Mitchell's journey from the coffeehouses of the Canadian prairies to her first international success with albums such as Clouds, Blue, and Ladies of the Canyon. Those records, which featured songs like "Both Sides Now," "The Circle Game," "Big Yellow Taxi," and "River" are still among her most popular and immediately recognizable material. Viewed from a narrow, commercial sense, Mitchell had already peaked by the early '70s and there must have been considerable pressure for her to continue making the kind of confessional, yearning folk songs that her growing audience clearly loved. But Mitchell has never been the kind of artist who made music simply to please people, so it wasn't surprising when at the height of her popularity, she ducked out of sight and retreated to her land on British Columbia's Sunshine Coast to reflect and reassess her journey up until that point.

The third archival set begins with material Mitchell recorded when she came out of seclusion to record For the Roses, a record that hinted at new musical directions yet still rested comfortably alongside her previous acoustic guitar-driven songs. Loose versions of "For the Roses," recorded with David Crosby and Graham Nash, and "You Turn Me On I'm a Radio," accompanied by Neil Young, reveal an artist at the absolute top of her game.

The real sea change in Mitchell's music is most easily heard in the demos and live recordings from the Court and Spark period, when she began to experiment with and incorporate jazz motifs into her songs. The arrangements and vocal phrasing are more complex and have almost completely moved away from the folk textures of her early music. Recordings from early sessions, featuring songs like "Help Me" and "People's Parties," show how hard Mitchell was pushing to achieve a new sound that was completely her own.

This journey continued with The Hissing of Summer Lawns, and for many of her fans, the recordings from these sessions will be the most interesting ones in the collection. Early versions of "In France They Kiss on Main Street" and "Jungle Line" show how far ahead of her time Mitchell was in 1974.

Like the material collected on the first two sets, the bare bones demos featured on Joni Mitchell Archives, Vol. 3 are not very different from the completed versions of the songs that made it onto the albums. Unlike Bob Dylan, who often experimented with different lyrics and arrangements, Mitchell does not appear to have ever gone into the studio without fully formed ideas about how a song should sound. What these recordings lack in surprise factor, though, they more than make up for in intimacy and immediacy and by giving listeners new ways to hear songs that long ago became very familiar.

Joni Mitchell Archives, Vol. 3: The Asylum Years (1972-1975) is out Oct. 6 via Rhino Records as a 5-CD set or curated 4-LP set.