She launched her triumphant show with her signature tune, "Big Yellow Taxi," performed 10 numbers spanning all her styles, and ended with her anthem for the '60's, "Woodstock".

She left a satiated audience projecting and sharing a sense of community all too rare in rock concerts.

She is Joni Mitchell, leading a band that's veritable roster of the best contemporary jazz musicians. She's coming off a controversial album that pays homage to the great jazz bassist Charles Mingus, and projecting an image of strength and daring in her performance that's not easy to associate with her recorded work.

She and her cohorts - Pat Metheny, guitar, a familiar face in the Burlington area; Jaco Pastorius, bass; Lyle Mays, keyboards; Michael Brecker, saxophone, and Don Alias, percussion - played for nearly two hours this week at Tanglewood in Lenox, Mass.

It was beautiful.

It's natural to expect sensitivity and sophistication from Mitchell, the mature Canadian who's traversed her country fields of 10 years ago ("Clouds", "Blue") to stalk the jazz alleys of race (all her albums since "The Hissing of Summer Lawns," 1975) What was not expected was how much of a rock 'n' roller Mitchell is, and how well she's managed to integrate jazz and rock, at least live.

"Big Yellow Taxi" was bright, insistent rock; "This Train," an older tune about a fading lover, was bittersweet, her dominant attitude; "In France They Kiss on Main Street" made Europe feel at home in America.

In the classical sense, her voice is a mezzo-soprano; but her control is overcome by her freedom, her need to express herself through that voice, swooping, crooning, shouting. Her enthusiasm was contagious; and even though some of the music was unusually demanding - especially the tunes from the new "Mingus" album, and her tortured passionate "Coyote".

It was clear she was enjoying herself. During her solo/voice reading of ("The Last Time I Saw Richard," an oldie from "Blue") she leaped into a nasty cockney to snarl out the waitress' putdown. It was funny, a relief, rather than a bitter.

Her interviews indicate she's a proud, idiosyncratic woman. Certainly her albums express her individuality, even though one doesn't necessarily agree with her experimentation. But onstage, she's happy, proud to be playing electric guitar with a band such as the one she's assembled. The show was organic. Sure, Methany, Pastorius, all of them took solos, and Pastorius, despite his undeniable virtuosity and way with a riff, might have been a little long. Still, as one soloed, the others would drop back, then come together in clusters, and finally as a full band to back Mitchell's voice.

They all PLAYED together, "Dreamland," from Mitchell's least successful album "Don Juan's Reckless Daughter," was a flat-out rhythmic delight, with Pastorius and Mays playing mean cowbell and block. Even Mingus' "Goodbye Porkpie Hat," with Mitchell's lyrics skirting bathos, turned out moving and smoky, true to the musical line.

Metheny may have been the most memorable soloist, though pastorius, playing his guitar horizontally, then jumping on it, was the high dramatic point.

Metheny spun cathedrals, possessed of fingers made for the guitar, the slim musician single noted his way around the instrument, creating harmonic masses that incorporated and transcended melody, forsaking logic for the sake of feeling. He plays guitar in a unique way: His sound is more like a synthesizer than anything else, and it's luminous.

As if her reading of "Amelia" (about womanhood and flight) and "Fury Sings The Blues" (homage to singer Furry Lewis, precursor of her Mingus tribute) weren't enough, she sang "Shadows and Light" approached the feeling of Gregorian chant, with its ecstatic musical empathy. Mitchell's conducting/choreography, May's organ, and its pointed synthesizing lyrics about good and evil.

It was over then, or at least it seemed to be. But the 12,000 plus people under the tent and on the lawn that balmy night clapped, shrieked, lit lighters, went all religious for Joni

So she came back and sang Frankie Lymon's "Why Do Fools Fall in Love?" with The Persuasions and full band, and it rocked and rhythmed and wasn't all blue. The crowd was in ecstasy.

Not enough. So Mitchell came out for the capper, a solo version of "Woodstock" that gave the lie to all those articles we've recently seen "commemorating" that event.

It gave the lie to the commentary because, 10 years after, Mitchell reminded us that indeed, "We are stardust/ We are golden." She certainly was in Lenox.