FOR ALL ITS blueberry muffins and rocking chairs, there is something disconcerting about Sisotowbell Lane, the rustic idyll that opens Side 2 of Joni Mitchell's debut album Song To A Seagull. The title lands oddly - Mitchell said it came from a Bronte-style mythology she was devising, an acronym for "Somehow, In Spite Of Troubles, Ours Will Be Ever Lasting Love" - but that's not the only peculiar note it strikes. The inhabitants of this bucolic commune might let you escape - "sometimes" they even lend you their car, says Mitchell over lulling, lotus-eating guitar - but rocking placidly in the window, they always watch for your return. "Go to the city/ You'll come back again," sings Mitchell in a siren-trill, "We wait for you."

While the "sweet well water and pickling jars" of Sisotowbell Lane are superficially appealing, there's something smothering here, the kind of controlling conformity that Mitchell had decisively rejected by the time she recorded Song To A Seagull in early 1968 with her then-lover David Crosby. At 24, she had already made at least three life-changing escapes from situations that could have stopped her in her artistic tracks - more, maybe, if you include the heavy threat of the iron lung that faced her when she contracted polio aged nine.

Before her mother Myrtle met Mitchell's father, Bill, she worked out the Depression as a teacher in a rural Saskatchewan school, instructing one all-ages classroom with her own hand-made books. "My family was accustomed to hardship," Mitchell said in 1995. "These were people reared in a complete pioneer set­ ting, and nobody thought to complain." Evidence of this pioneer spirit could perhaps be detected in their daughter's inclination for forward motion, new ground, restless evolution. "I was born to chase a dream," she sang on early song Born To Take The Highway, while on the pre-fame Urge For Going she watches "the geese in chevron flight" and realises "all that stays is dying/All that lives is getting out".

Getting out was, however, a treacherous game. Born at Fort McLeod army base on November 7, 1943 and named Roberta Joan Anderson, Mitchell has described an austere, post-war childhood: snow, sickness, Victorian morality. Working as a "wholesale model" in front of travelling rag trade salesman, Mitchell raised enough money to pay for art school, yet her love of folk music soon drew her towards Toronto's coffee-house scene. Her flight was stilled when she became pregnant; unable to tell her parents, she survived on bread and cheese, living in a disreputable boarding-house where previous tenants had used the banisters for firewood.

When her baby was born in February 1965, Mitchell placed her in foster care, clutching at nuclear- family straws by marrying folk-singer Chuck Mitchell in June that year. They moved to Detroit, yet her husband quickly proved incapable of handling Mitchell's spirit, ambition and talent. "He would have to do a considerable amount of grooming for me to be a suitable partner, and I tended to rebel," said Mitchell in 1983. "I was a day dreamer, unfocused, a very young 21 when I got married."

With the mirage of domestic stability fading, she decided that her daughter should be adopted, leaving Chuck for New York and then LA.

No wonder then, Song To A Seagull is so obsessed with the pursuit and promise of freedom. By the time Mitchell was recording these songs, the world had already tried to pin her into place repeatedly; it made sense, as she sings on the tide track's dip and whirl, that she should have a love for "the freedom of all flying things". Her songwriting was one uplifting current - a 1968 piece in the New York Free press was headlined 'The Industry Likes Joni Mitchell', acknowledging her songs had been covered by Judy Collins, Tom Rush and Buffy Sainte-Marie.

Her debut, however, was her own statement of independence. Dominated by her lush floral artwork, Song To A Seagull's sleeve features a small photograph of the singer, her guitar and case marking her out as wandering minstrel, the freewheeling Joni Mitchell. Side 1 (or "Part One") is subtitled "I came to the city"; Part Two is "Out of the city and down to the seaside". This is a journey - not a boring modern reality TV one, but an epic odyssey, full of mythical lovers and avian auguries, pirates and mermaids, ships and, depending on your interpretation of irascible cab driver Nathan La Franeer, strange boatmen.

FROM OPENING TRACK I Had A King she spins the everyday - brooms, curtains, "drip- dry and paisley" - into gold, elevating her failed marriage into fairytale, luscious language possibly cushioning the pain a little. "I can't go back there anymore/You know my keys won't fit the door," she sings with quivering distress (Chuck did actually change the locks on their apartment.) "The rooms have an empty ring," meanwhile, has a sly double meaning in a song about packing up a marriage. She's slipped from another trap.

If the "king" spends time "painting the pastel walls brown" - unforgiveable on a record so alert to colour and its meanings - on the gentle, blossomy Michael From Mountains, Mitchell finds a man who understands rainbows, making "coloured arrangements" with the "oil on the puddles in taffeta patterns". It might not be forever, but it does hopefully suggest a different power dynamic between a man and woman.

At the time of recording, at least, Mitchell appreciated Crosby's light production touch, his commitment to keeping orchestra-happy record executives at bay. In an interview, she imitated his voice: "T don't want to hear you rocked up, so I'm going to pretend to rock you - but I'm not going to do it.'"

They had met at her show at Miami's Gaslight Club in autumn 1967; sailor Crosby, seeking his own seaborne escape, fell for her "immediately". Mitchell would mythologise Crosby on The Dawntreader, her "chords of inquiry" gently pushing out into the water like those "gilded galleons". Ominously, however, it's followed by the discordant The Pirate Of Penance, a nautical Murder Mystery delivered in eerie overlapping vocals between "The Dancer" and "Penance Crane". Happy-ever-after is not a given.

Even when she doesn't cloak the everyday in legend, nothing on Sony To A Seagull feels quite solid. Night In The City lets in the outside world - not least because it features Stephen Stills on bass - but its hedonistic, honky-tonk roll is still a confusion of colour and noise, while Nathan La Franeer is suddenly distorted by a "banshee" blast, as destabilising as the image of "an aging cripple selling Superman balloons". The city, it turns out, is still a lonely place: Marcie is a New York Eleanor Rigby in waiting, a tender study in loneliness.

Yet as Song To A Seagull suggests, it is only by being untied - from conventional relationships, from conven­tional chord formations - that freedom is possible, a sentiment caught in the gathered momentum of Cactus Tree. Mitchell sings of a "lady in the city" pursued by a string of lovers. Her joy in their love is, however, tempered by the fear "one will ask her for eternity/ And she's so busy being free".

Mitchell might veil these songs in layers of mythical gauze, but underneath Sony To A Seagull is an act of bridge-burning, a bold untethering. You can never go home again, but no matter: a candle might be burning in Sisotowbell Lane, but that's not the dream she was ever born to chase.