One day in the summer of 1963, a young woman wandered into the recording studio of a radio station in Saskatoon, the largest city in the southern prairie-land province of Saskatchewan, Canada.
She wore her hair in a flipped bob, the vogue of the times: the Jackie Kennedy cut.
In her hand she carried a Harmony baritone ukelele, her preferred instrument, for the earthy timbre of its nylon strings brushing against its solid mahogany body.
She was a folk singer, playing now and again in the coffeeshops and clubs of her home city, but her name was otherwise unknown. Roberta Joan Anderson.
She sat on a stool in the studio, positioned her fingers on the ukelele, and awaited her cue from the night-shift deejay, Barry Bowman.
She started playing, frisking a curlicue of plaintive notes in open tuning, a habit she had devised to compensate for the weakness in her left hand, the result of a childhood bout of polio.
Then she sang, her soprano as clear as a bell ringing to the heavens, sustained by a vibrato that shimmered like a low-burning flame.
The song, a traditional ballad dating from the turn of the 20th Century, was a staple of the folk scene, a cautionary tale told by a vagabond, lamenting a life led astray.
"There is a house in New Orleans," she sang, "they call the Rising Sun. It's been the ruin of many a poor girl, and me, oh God, for one."
She sang another eight songs after that, and the deejay put the tapes away, and he carried on with his life, and she with hers, performing on the folk circuit with her husband, Chuck Mitchell, using a diminutive of her middle name: Joni.
She would go on to become one of the most acclaimed singer-songwriters of her generation, famed as much for her dreamy, painterly lyrics as for the restless inventiveness of her music, and its seductive flirtations with form and structure.
Barry Bowman, the deejay, meanwhile, would long regret misplacing the tapes of that debut recording session by Joni Mitchell, until the day, more than half-a-century later, that his daughter brought him a box of paraphernalia she had discovered in the basement of their old house.
And there were the two reel-to-reels, their cartons marked: Joni Anderson Audition.
Now their contents, recorded when the singer was only 19, stand at the centrepoint of "Joni Mitchell Archives Vol. 1: The Early Years (1963-1967)", a collection of 119 songs spanning almost six hours of studio and live material, and released today on the music-streaming platforms, on the cusp of Joni's 77th birthday next week.
But the most haunting song of them all is the opener, House of the Rising Sun, for the glimpse it gives us of a rising talent in its genesis, and for reminding us that as much as we may think we know a singer and their songs, there is always a revelation awaiting us in the faraway mists of time.