A remarkable new box set lets you listen in as Joan Anderson, an obscure folksinger from Western Canada, turns into the internationally beloved artist known as Joni Mitchell. Called Joni Mitchell Archives, Vol. 1: The Early Years (1963 - 1967), the five-disc collection consists entirely of live performances that (bootlegs aside) have not previously seen the light of day. There are also lots of spoken intros to songs in which Mitchell comments about her material, often in ways that shed new light on it. The handsomely boxed collection incorporates a 40-page booklet with archival photos and a lengthy new interview with Mitchell by Cameron Crowe.

Disc One features her earliest known recordings, including a radio broadcast tentatively pegged to 1963, a two-set 1964 performance at a Toronto club where the applause after each song conjures up an audience of perhaps a dozen people; and even a few numbers recorded in early 1965 at Mitchell's parents' house in Saskatchewan. Throughout this CD, she sounds as if she's auditioning for the role of Joan Baez's understudy as she performs such traditional numbers as "House of the Rising Sun" and "John Hardy" as well as Woody Guthrie's "Pastures of Plenty" and "Deportee (Plane Crash at Los Gatos)." Her voice is already gorgeous, and her phrasing and guitar work are often distinctive, but with not a single original song in the batch there are few hints of what lies ahead.

Those hints start showing up right at the beginning of Disc Two, which - like the three CDs that follow - consists almost entirely of Mitchell's original material. The album opens with a three-song birthday tape that she made for her mother. "I've written a couple of new songs...and I think you'll like this one especially, Mom," she says before launching into the now-classic "Urge for Going." Also on the disc are a 1965 demo for Elektra Records' Jac Holzman, Canadian TV performances from 1965 and 1966, and a 1966 Philadelphia concert that includes "The Circle Game."

That number, incidentally, is the title track of a 1968 Tom Rush album that also offers Mitchell's "Urge for Going" and "Tin Angel" and that helped to widen her audience. Here, she introduces "The Circle Game" by saying, "I guess my best ambassador is a fellow named Tom Rush."

By the time we get to Discs Three, Four, and Five - which contain radio and concert performances, home demos, and another birthday tape, all from 1967 - it's clear that Mitchell isn't going to need ambassadors for long. Melodic, lyrically first-rate compositions are pouring out of her, including numbers that would feature on her 1968 debut album, Song to a Seagull ("Michael from Mountains," "Night in the City," "Marcie," "I Had a King," the title track) and such subsequent releases as 1969's Clouds ("Chelsea Morning," "Tin Angel," "I Don't Know Where I Stand," "Both Sides Now," "Songs to Aging Children Come"), 1970's Ladies of the Canyon ("Morning Morgantown," "Conversation," "The Circle Game"), and 1971's Blue ("Little Green"). Also here are 29 mostly excellent original compositions that never made it onto any of her studio LPs.

Like Bob Dylan before her, Mitchell transitioned almost overnight from being an impressive but derivative covers artist to an original singer/songwriter of major proportions. Archives, Vol. 1 gives you a taste of the covers and a big helping of the star-making gems that quickly followed.