The myth is spun in sacred vinyl and remembered spotlights. In swirling soprano self-portraits and worshipful press clippings, all cornsilk flashes and free-spirit poetry. There is no myth in the top of pop quite like it.

Carole King and Helen Reddy sell more records, but what is magical about women's lib or baking banana bread and driving your kids to school in a pick up truck? Roberta Flack sings with more soul, but what is there to catch a body's imagination about living with your mother in Washington DC?

No, Joni Mitchell clearly has the edge on enchantment, an edge totally untarnished by six albums of stark self-revelation, caustic self-accusation and contrary indications of a sometimes sordid reality.

She sings that she is fickle, and that her heart is full and hollow like a cactus tree 'cause she's so busy being free, but they only seem to remember the romantic elusiveness. She sings guiltily about her greed for fame and fortune, but they only seem to hear the artful imagery.

Through it all, though, through the 10-year career knocking around the Toronto coffeehouse circuit, booking herself right into recognition and sustained sometimes only by her own steely drive, through all the loves and losses that read like a gossip roster of Who's Who in rock 'n' roll, she has emerged unscathed in portraits of enchanted dewdrop vulnerability.

And if absence only makes enchantment grow fonder, she will walk out onstage at the University of Waterloo tonight or Massey Hall tomorrow after a two-year retreat from the public glare as queen of the cults still intact, immaculate, preserved forever as the elusive pastel prairie wildflower, the misty wispy moonbeam princess lushly chording in her castle of bittersweet sorrows and stained-glass dreams.

They will not see a tall, thin blonde with features just a shade too sharp and teeth too numerous to be really pretty, a deft self-propelled superstar who has survived the millions and minions and a decade of musical history, to live now in half a Beverly Hills' mansion that Julie Andrews used to own, see her psychologist twice a week and date Warren Beatty and assorted rock stars as countless as "railroad cars," which is about as Hollywood as you can get; who likes to eat out at classy restaurants and go bowling, which is about as unpoetic as you can get; and who just passed her thirtieth birthday.

They will not see the girl who friends say has changed, no longer acts so strange, is more sophisticated, worldly, womanly, has let her decolletage dip down for her newest publicity photos and her folkie bangs grow out.

They probably wouldn't want to see her, either, just a week or so ago on this sleazy fringe of Sunset Strip just down the street from Deep Throat, the Venus Massage Parlor and the Institute of Oral Sex, up a darkened alley and behind a fortress-like grated iron gate here in this all-night rehearsal hall where she comes storming down the corridor past the pay-phone and the pin-ball machines and the pool table in the lobby, muttering the unmistakable pear-shaped sounds of a four letter word.

Joni Mitchell has just been told there's a journalist in the hallway and she is not exactly enthusiastic about journalists ever since Rolling Stone, the rock bible, chronicled her romances with Graham Nash, David Crosby, Leonard Cohen and James Taylor, among others, complete with convoluted hearts-and-arrow graph charts, and somewhat unkindly christened her "old lady of the year." Now, Joni Mitchell extends a limp and wary wrist and makes it quite clear she doesn't do interviews anymore.

"I've had some bad experiences," she'll admit much later that night. "And besides, I just don't find these things very interesting reading."

So she writes her own press releases, like the one for her newest album in her child-like loopy longhand, a little short on details and little long on preserving the mythology.

"I was born in Fort Macleod, Alberta, in the foothills of the Canadian Rockies - an area of extreme temperatures and mirages," she lyricises.

"When I was two feet off the ground I collected broken glass and bats. When I was three feet off the ground I made drawings of animals and forest fires. When I was four feet off the ground I began to dance to rock 'n' roll and sing the top 10 and bawdy service songs around camp fires and someone turned me on to Lambert, Hendricks and Ross and Miles Davis. And later Bob Dylan. Through these vertical spurts there was briefly the church choir, Grade 1 piano, bowling, art college, the twist, a marriage, runs in the nylons and always romance - extremes in temperature and mirages."

Others who have been a little less liberal with the mirages have recorded that she was born Roberta Joan Anderson, grew up in Saskatoon the daughter of a grocery man who used to blow trumpet and a onetime country school teacher who used to know the names of all the wildflowers, that she doodled her way all through school, learned her love of words from her Grade 7 teacher, Mr Kratzman, but always wanted to be a painter till she was waylaid at Calgary art college with a romance with a coffeehouse called The Depression and a Pete Seeger do-it-yourself record that taught her to play guitar.

She dropped out to tote her dreams and schemes into the Toronto folk scene in 1964, where Riverboat owner Bernie Fielder, now her friend and promoter, offered her a job as a dishwasher, which he says was just a joke, although she doesn't remember it quite that way. But, by that time Joni Mitchell knew just where she was going and she went there straight up, till suddenly it all got too much for her two years ago and she dropped right out of the glare.

Now, on this, the last night of rehearsal before she hits the road for her personal comeback, she is warmed up, wound up and admittedly nervous because it's the first time that she's shared the stage with a band, Tom Scott and the LA Express, and things are, she says, "a little shaky."

But she invites you in anyway, "not as the press but as a friend," although ironically, a week before she had talked to old folk-singing friend Malka (of Malka and Joso), not as a friend, but as the press. She was glad to have the band, she told Malka on CBC radio's Entertainers, "to absorb some of the lonliness….I don't want to be vulnerable."

She perches on an equipment trunk to watch them warm up now, wedged between a bottle of vodka and Liebfraumilch, wearing the pastel colours she paints in, pink pants and high-stepping '30s pink slings, prim white blouse and yellow chamois jacket, her fingers all brand new gold rings, her waist all flowers in an antique cloisonne belt. She sips white wine and a cigarette dangles through her long languid fingers. "I'm excited," she says "'cause I really like these guys."

But at the break it becomes clear that she's excited too because she really likes one of them, drummer John Guerin, a lean, elfin good-looker, a little better than the rest. They kneel together, arms entwined…and she brings him comic newspaper clippings, snaps polaroid photos of him and follows him out into the hall.

As one of her friends says, "There's no need for interviews. She says it all in her songs. Whatever's going on in her life, she says in her music. In her writing, Joni's the frankest person I know."

Indeed, she sits down now at the piano and chords out the reasons for her retirement in the songs about the street busker who played real good for free….

It [the song 'For Free'] was written when "the money and success seemed distasteful. The fame and fortune seemed out of all proportion to what I was doing, although there were times I felt I deserved every bit of it….I felt a little whorish about selling my soul, putting a price on it. I would get up and pour out fragments of it for money and applause, not only my life but sometimes the life of someone I was with in a close personal relationship."

She had poured out the end of her three year marriage to Detroit folk-singer Chuck Mitchell years ago in "I had a King in a salt-rusted carriage / Who carried me off to his country for marriage too soon."

Thirty six hours after they met, they formed a duo; he gave her his name and in many ways her start. It was his friends like Tom Rush staying at their house who first heard and recorded Joni Mitchell tunes. As she told Malka, "Then I began to long for my own growth. As soon as the duo dissolved, the marriage dissolved."

But years ago she confessed, "I guess the thing that bust it was when I started making more money. That hurt a lot."

But that wasn't what made Joni Mitchell want to quit the business. The relationship that left [the] most marks on the singer and her songs was the one with James Taylor, who she met on Toronto Island after a Mariposa Folk Festival, all chronicled in bittersweetness and goodbyes on her last two albums, 'For the Roses' and 'Blue.'

She belts out his battle with heroin in 'Cold Blue Steel and Sweet Fire,' keens at her own lonely sense of feeling left out as she gave up working and traipsed after him as he made his one abortive movie, 'Two Lane Black Top': "Your friends protect you / scrutinise me / ……Oh baby, I can't seem to make it with you socially."

She sings now, "You can't hold the hand of a rock 'n' roll man."

"The rock 'n' roll industry is very incestuous," she confesses. "We have all interacted. James, he's written songs for me, I've written songs for him. A lot of beautiful music came from it, a lot of beautiful times. And a lot of pain came from it too, because inevitably relationships broke up."

When Joni Mitchell and Taylor started slowly coming apart two years ago, she retreated to the house she built out of rock on a promontory of Half Moon Bay on Vancouver Island, a house that she hasn't been near in a long time now, though its stands there still. "Almost like a monastery. All stone and hardwood floors and hardwood benches, everything that would be corrective. No mirrors. Fighting for all that good virtue in myself," she says. "when I left my house in Laurel Canyon I looked around and it seemed too soft, too comfortable, too dimly lit, too much red upholstery.……It was really ridiculous. I just made this place really uncomfortable, like a corrective shoe."

She retired into travelling and painting, and that Christmas all her friends got a special, exquisite limited edition silver book of her songs, hand-written our beside bright fine-line felt-pen drawings, one of them unmistakably a picture of James Taylor on a bright green bedspread, pale and unstrung.

She started psychoanalysis "to talk to someone about confusion," she says, "and I was willing to pay for his discretion….

"An artist needs a certain amount of turmoil and confusion and I've created out of that, even severe depression. But I had a lot of questions about myself, the way I was conducting my lives - life, what were my values in this time. Most of it was moral confusion…..I'm your average quiet-ridden person," she says.

Still, it might not have been quite as easy as she makes it sound, for later there's a truer ring as she sings "Trouble Child." "So why does it come as a shock / To know you really have no one / Only a river of changing faces / Looking for an ocean…."

But out of all the soggy dreams and isolation and time on her hands, one answer came back loud and clear.

"I heard it in the wind last night," she sings. "It sounded like applause…."

The lure of what she calls onstage "An almost euphoric feeling….sometimes I've felt out of control with it, I no longer was myself. I was transported…" in the end transported Joni Mitchell right back into the spotlight.

As she says, "I was too young to be retired at 27. I didn't know what to do with myself."

She played a James Bay Indian benefit in Montreal and another in Topanga canyon last summer to get over the old loss of nerve that had once gotten so out of hand she'd stalk off stage in mid-song "if anything fluttered in the room."

Now, up on this tiny rehearsal stage, going through the set a second faultless time, there's little doubt about how glad she is to get back. The first set's gone well, but something still finer is happening this time. The horns and heavier percussion take off with her high piercing soprano. The room goes electric. A long, liquid brown beauty, all flying hair and turquoises, takes to the floor and starts to boogy to the rhythms, all alone, oblivious. "Magic," she says, "has arrived."

You watch the face up on the stage that changes almost as fast as the incredible guitar finger-work, from the toothy, giggling schoolgirl gossiping at the break about short haircuts and new silver earrings, to the shy, moony eyed maid eyeing her new man, now the wanton rocker, all grit and tumbleweed.

And you realise that it wasn't just a slip of the tongue when in mid-sentence she caught herself talking about not her life but her "lives." There are paradoxes here beneath the myth, myths buried deep still beneath the bowl-o-rama cool rocker reality. "It's all part of that [I] guess," she says, "will the real me please stand up."

Joni Mitchell's still singing about waiting for her prince to ride up, only this time she sounds a little more upbeat about it, a little less wild flower vulnerable, a little less victimised. The songs are mellower, matured and maybe the best work she has ever done.

She tosses her long blond mane back, but now there isn't quite so much to toss.

"The thing is," says Joni Mitchell eyeing her myth separately across the studio's back wall mirror, "you can express all these high and beautiful thoughts, but your life may not back it up."