WHEN she left Toronto, the scene changed little. A few followers, maybe, left in the stillness of her leaving; perhaps a lover or two. Her gentleness hadn't imposed itself; when she sang at the Riverboat most heads had congealed around her, settling like fine dust.

Atmospheric, the wiser had said about her songs. Atmospheric, quaint and rootless. Coming from Saskatoon, natural imagery crowded her lyrics; a love of the land. But everything was sketched in watercolors, her voice swooping, flute-like over breathless melodies. Things always seemed a bit unreal, intangible, as if Joni (Anderson) Mitchell was floating up there somewhere, over the things she sang about.

People searched for categories. But it was as if Debussy had gone pop. Mistily impressionistic, her songs were oddly unique. There was Baez, Collins, Ste. Marie, Ian - still Joni was Joni.

Nothing she did fit any convenient pattern. Her guitar playing constructed chords few textbooks mentioned. Her melodies seemed stylistically caught somewhere between Gregorian Chant and gritty blues.

But who was worrying about all this a year or so ago? It was her poems, the words, that had become the touchstones to her insight. In the Wizard of Is, an old song, Joni sang about "the happy ending stories that you hear."

Any blues then were in pastel; sadness was often fragile; "She'll . . . dust her tables with his shirt and wave another day goodbye."

And for a while, Toronto held its breath watching her. Lovely, frail Joni, high-cheeked boned and square-jawed; a Miranda, slightly intimidated by her brave new world.

Then it was as if anything harsh would snap her in two. Travelling out and back again, everything only seemed to increase her capacity for wonder and words. Social causes, Important Issues for her seemed to exist on another plane. "To protest always seemed ironic to me," she once said at the Riverboat, "for who do you reach? Those who like your songs agree with you; those who don't won't listen."

Some were. Tom Rush picked up one of her songs, Urge For Going in Detroit and gradually her fame spread through folk music. Then the disappeared, moving to Laurel Canyon in Los Angeles.

Down there, things were in the works. It was reported, the Big Time. Everything started to become over-blown; that is until her album, Songs To A Seagull came out on Warner Brothers-Seven Arts. No record could have been more underblown.

This album is dedicated to Mr. Kratzman, who taught me to love words.

And that's all. The record was extravagantly put out; Joni had designed the flowery swirling painting. And there walking alone was the singer. But this was all. No liner notes, no biography. Just the lyrics and the dedication to Kratzman. Period.

Kratzman? More of her history started to expand. No, it was explained, Kratzman wasn't Leonard Cohen, no. It was her old high school teacher, an Australian who taught her English. And, apparently, the love of words.

Songs to a Seagull was slightly remarkable. Its impact was large, but not, particularly, its sales. In it, things were smoother than before; listening to it was like putting your ear up to an empty room, hearing words frozen while warm.

Words. She loves their private connections, their individual reverberations. They spill all over her second album, Clouds, as Joni sketches in a Chelsea Morning, a circus midway, galleries and roses.

IN CLOUDS, the carry-over in mood from the first album is almost left intact. There's the sense of the reiteration of a statement, as if she herself produced that mood and was beautiful once by its dream. O.K., you say, things are peaceful in Laurel Canyon, the Maxfield Parrish pictures, the art nouveau lamp, the flowering azaleas there and all.

And now, 25 she's with ex-Holly, Graham Nash, and both are working on new albums, he with a new super-group record with ex-Byrd David Crosby and Steve Stills, one with the Buffalo Springfield. Everything's away from the city there, and dirt roads lead to friends.

Her songs still are like tinted snap-shots of reality. "But the reality's getting grimmer," she says. "California's really a beautiful place to live - but you can get too complacent, too comfortable. I went back to New York a little while ago for five days. It was like a hard, cold drink of reality.

"For me, I think California is just a cooling out place. But stay? Everything here seems very temporary to me. I still love it. There's all kinds of change going on down here. The whole culture has almost become strange with creative people."

There was a pause, perhaps as the psychological pendulum swung the other way. Yes, she went on; things were happy. But "But I think we need reality. It's . . . it's that we need to be educated by reality. Right now, now as you're talking, I am only concerned about things close to me. About my man; about getting married.

Her 1965 marriage to folk-singer Chuck Mitchell, the time when she went to live with him in Detroit, was described after it had ended in I Had a King - rarely have the public and the private been too far from each other.

A Pete Seeger guitar manual taught her how to play, an Australian English teacher taught her how to write. Everything else seems to have been taken by some form of osmosis.

Cohen's lyrics touch her spirit with his mind; and Dylan - the man "who's been sailing in a decade full of dreams" - thickened things up a bit, making words add a new convoluted twist.

OUT folk, for the recent period of time folding the self-designing folk-boom in the earlier Sixties, was a bit of a hot-house flower. Either a folk-singer made it - big! - or he went into rock, or he sat starving in clubs mumbling metaphysics about himself and not much else.

The Canadian experience produced songs like L'Hiver, and the Canadian Railroad Trilogy, songs reflecting the existence in unrelenting conditions. The American experience was reflected by lyrics of the more sociological bent. Chicago and the siege of the establishment just couldn't be escaped; and riots and revolutions were converted into rhythms.

EVEN, it seems, in Laurel Canyon during the Americanization of Joni. "Perhaps I am becoming more American," she goes on. "I'm very concerned with the problems down here; I really feel that work's to be done" - all this said very seriously. Then she pauses again: "But I'm just one person. One person. But, too . . . I feel this way is important.

"You see, I've had more, uh, socially orientated songs all along! I just didn't want to record them. I just don't want to point fingers. Everytime I feel a certain way about something, I hear an argument for the other side. I'm just a hopeless middleman.

"I'd like to express my thoughts socially, but in a way where there's no two sides. You know: Don't duck the draft; don't join the army. I'm not exactly being clear here, but what I want is something in the middle.

"I've just been reading something by this fantastic man from Harvard. (Dr. George Wald; the article's in the Los Angeles publication, Planet People.) He makes many points; he shows how un- American the compulsive draft is; that the Pentagon after World War II has built up a head of steam that can't be stopped. You see, that I'm now looking for is not something more abstract than this . . ."

You just can't mess around any more, she was saying. You just can't: "All this must sound evangelistic and crazy. But everybody's looking for the one who will sing the song that will save the world. And I just couldn't sit up there in Canada reading the newspaper."

"Down here in California, people realize that they can't stop being cool. Canada's so much a freer place than the States. People are being shot down here for their beliefs - as this all the though about husband and career and the third and fourth albums she was planning evaporated.

"A few months ago an American Senator got up and said that if Adam and Eve were to be born again, he'd want them to be American. The Harvard professor thought that was criminally insane.

"But I'm still writing love songs and words about what happens to me. I'm still trying to keep up what's inside. I don't think I really want to add more songs to people at my concerts who are already heart-sick.

"I stick pretty close to people. I'm not a tele- phoner, or a letter-writer. I have to be in a place like here where there's more of a person-to-person contact. Do you get to understand others through smiling like you? Maybe. I don't know.

"That's why I'll probably eventually settle in Canada, but only in the country. But right now, I don't want to be too far off. I feel I'm needed here like a doctor. Yes, I'm needed."

In the background - here's? Or mine? It was difficult to tell - a section of Clouds were being played. It started at The Angel where "In a Bleeker St. cafe, I found someone to love today." Then Clouds moved with its yellow curtains and crimson crystal beads.

Sunny, Joni, strange, feminine, haunting. What had Kratzman to do and to you? Then in Both Sides Now, and old song, something came:

I've looked at life from both sides now From up and down, and still somehow It's life's illusions I recall I really don't know life at all.

But, she would say, that's O.K. Life, love - you've got to be needed. I felt the Mickey Spillane in the night recall. Yes, she would say, but . . .

Joni Mitchell will be appearing at the Mariposa Folk Festival, July 25-7.