Joni Mitchell Archives Vol. 4 appears to be comparatively sparing in outtakes or demos, but it's rich in what too many box sets skimp on: a wide-ranging spread of live recordings. In this case, they demonstrate how Mitchell's songs evolved on stage as well as in the studio, documenting a genius at work.

Joni Mitchell Archives Vol. 4: 6 CDs or 4 LPs, $99.98. [Features unreleased studio sessions, alternate versions, live recordings, rarities, and 36-page book with new photos as well as an extensive conversation between Joni Mitchell and Cameron Crowe. Sourced From Original Stereo Reels, Nagra Film Recordings, Multi-track Tapes, Radio Airchecks & Cassette Tapes]

Joni Mitchell blooms anew in each gradual step of her public comeback. From the 2022 Newport Folk Festival to recent Hollywood Bowl concerts where she dug deeper into her repertoire with lead vocal turns, her now-deepened voice still mesmerizes in a victory lap never imagined after a 2015 brain aneurysm.

But fans can truly hear Mitchell at the peak of her powers on the new box set Joni Mitchell Archives Vol. 4, which looks back at her Asylum Records period from 1976-1980 (though the set includes late 1975 live tracks). That era was highlighted by her enchanting landmark travelogue Hejira and extended through Mingus, a project with that iconic bassist/composer where she adapted jazz to her own creative whims, her lithe soprano darting and daring beyond the constructs of folk-pop.

Arriving as Mitchell turned 81, the 6 CD/digital collection (also available on 4 LPs) is anchored by March 1976 demos of seven songs that formed the bulk of Hejira - plus a few held for follow-up Don Juan's Restless Daughter. Stripped to her voice and acoustic guitar, the tracks nonetheless present the material as fully formed; Michell is flowing in her poetic turns of phrase and brisk playing, her vocals relaxed and jazzier in "Blue Motel Room." "Black Crow" contains a twist: backing vocals from Chaka Khan that are both interesting and distracting. Mitchell can handle her own singing, as she proves later in Mingus alternate track "Sweet Sucker Dance." It's practically a cappella over Don Alias' brushed drums, her multitracked voice suggesting ghostly siren calls - in contrast to a straightforward alternate take with a trio led by Gerry Mulligan's baritone sax. Charles Mingus even surfaces to talk through "A Good Suit and a Good Haircut," sharing memories and opinions about music and life.

Other Mingus alternate tracks reveal an experiment in which Mitchell tapped a larger lineup. But players known for their powerhouse touch - namely John McLaughlin on guitar, Stanley Clarke on bass, Jan Hammer on mini-Moog and Tony Williams on drums - are barely evident. In the end, Mitchell favored a sparse palette with a choice of musicians (largely from fusion group Weather Report) anchored by sympatico fretless bassist Jaco Pastorius, who entered her orbit for Hejira and underpins Wayne Shorter's soprano sax and Mitchell's guitar here in "The Wolf That Lives in Lindsey." Yet one of the set's greatest studio outtakes is "Save Magic," Mitchell's 12-minute solo piano improvisation, an embryonic version of Don Juan's majestic centerpiece "Paprika Plains." Quietly captured by trusted producer Henry Lewy, who knew when to roll tape, it's a concerto-styled jaunt that recalls the probing, pondering improvisations of pianist Keith Jarrett - and stands apart from most everything in the box.

But if Joni Mitchell Archives Vol. 4 appears comparatively sparing in outtakes or demos, it's rich in what too many box sets skimp on: a wide-ranging spread of live recordings. In this case, they demonstrate how Mitchell's songs evolved on stage as well as in the studio, documenting a genius at work.

The set opens with several tracks from 1975, when the singer opened for Bob Dylan's Rolling Thunder Revue through the Northeast, a trip she describes to one audience as "kind of like running away from home to join the circus." This entry includes loose band forays from Harvard Square Theatre that include David Bowie axe-man Mick Ronson as well as T Bone Burnett, plus intimate solo turns in a chatty, informal "A Case of You" (floating on her ethereal voice) and - at Gordon Lightfoot's house - "Woman of Heart and Mind." Then, as the tour moves to Montreal that December, Mitchell unveils "Coyote," the soon-to-be lead track of Hejira about a flirtation with playwright Sam Shepard, its glorious weave already secured despite an incomplete fourth verse.

The growth of "Coyote" was rapid. The song arrives at its more refined, confident version two months later at Boston's Music Hall, where it's segued into "Don Juan's Reckless Daughter," the title track of the next album after Hejira. That February 19 Music Hall concert provides 18 of 23 tracks that showcase her 1976 tour in the running order of its setlist. The material ranges from the beautiful flow of the hits "Help Me" and "In France They Kiss on Main Street" (the singer's last note flying high away) to the Burundi drummer-inspired "The Jungle Line" (punctuated with a synth line that chirps like an old video game) and "For Free," a piano-rooted vignette about a street musician's freedom where Mitchell stuffs in ad-libs about all her newfound handlers. The band includes her then-boyfriend John Guerin (drums), Robben Ford (guitar), Victor Feldman (keys), and David Luell, whose woodwinds sweetly ice "Just Like This Train" and "Cold Blue Steel and Sweet Fire." Notably, Mitchell also sings "Traveling," an early version of Hejira's title track that's laced with shuffled verse and verses before it received a just trim. "Traveling" and "Coyote/Don Juan's Reckless Daughter" also surface in the 1976 studio demos.

But again, while studio sessions thread throughout the set, it's the live tracks that stand out - predominately with good sound quality. They include a 1976 Rolling Thunder return with a nine-minute take on the ruminative "Song for Sharon" (which lets her storytelling engage without its atmospheric choruses on Hejira) and a jaunty "Big Yellow Taxi" at a 1979 Coalition Rally Against Nuclear Power where Graham Nash, Jackson Browne, Dan Fogelberg, and John Hall provide backing vocals and Mitchell sings "They paved paradise, and they put up a nuclear hot spot."

Mingus tunes receive an illuminating test drive at Berkeley's Greek Theatre for the 1978 Bread and Roses Festival. At the end of her playful solo a cappella "The Dry Cleaner From Des Moines," a laughing Mitchell responds to a catcall with "That ain't rock 'n' roll, man, that's bebop," and she inspires the audience to mimic wolf calls over brash guitar tunings in "The Wolf That Lives in Lindsey." Best of all, she brings out pianist Herbie Hancock to accompany her on "A Chair in the Sky" and an especially sublime "Goodbye Porkpie Hat."

The set's live tracks culminate in more than a disc and a half from 1979, the tour that yielded the 1980 live album Shadows and Light. Most of the tracks here were recorded at an early tour stop in Forest Hills, N.Y., again in the order they were played (the "Woodstock" encore is tacked on from a Philadelphia show a few nights later). Her jazz-centric band was widely considered one of her best and certainly most unique, featuring Pastorius, guitarist Pat Metheny, keyboardist Lyle Mays, saxophonist Michael Brecker, and Alias, on drums as well as his usual percussion. And they're radiating fresh joy in Forest Hills.

After opening nuggets like "Big Yellow Taxi" and "In France They Kiss on the Main Street," the concert leans into the late '70s repertoire that this box mainly explores. "Coyote" returns as a highlight given the sonic shadings of Metheny and reverberating harmonics of Pastorius, who also wields that touch in a double-tracked mid-set solo that teases Hendrix. Alias' congas solo slides into Mitchell's facile vocal showcase "Dreamland" while "Black Crow" swirls into a Brecker tenor-topped tempest. The band rocks "Raised on Robbery" and Mitchell nods to her 1971 jewel Blue with piano ballad "The Last Time I Saw Richard," while vocal group the Persuasions bolster "Shadows and Light" and Frankie Lymon and the Teenagers' "Why Do Fools Fall in Love," a doo-wop oldie that taps one of Mitchell's past inspirations as she forges her future legacy.

Mitchell's output in the second half of the '70s widened her risky choices in personal lyrics, odd tunings, jazz complexities, and emotional simplicities. And this fourth volume from her archives is nirvana for fans of the singer's most adventurous travels, starting with those like me who view Hejira as a holy grail.

The box set's packaging includes welcome liner notes and photos, plus a recent interview of the artist by Cameron Crowe - where she says that Dolly Parton's response to a playback of Hejira was "If I thought that deep, I'd scare myself to death." Yes, perhaps best of all, Mitchell was personally involved in curating this fabulous collection, and she's still here to enjoy the victory lap.