For a superfan I've not been very diligent with Joni Mitchell's back catalogue (comprising 19 studio albums recorded over 39 years, several live ones and an ever-increasing volume of compilations). My relationship with her music broadly begins with 1969's Clouds and until recently, save a few random tracks, it ended with 1976's Hejira. In some ways, this curtailment of her oeuvre has been intentional. I wanted there to be more Joni currency in the bank - a little like knowing there are 12 seasons of a show I'm bound to love held in reserve to comfort me during a depressive spell.

But on the flip side, there's trepidation. Perhaps the sheer quantity of her records could dilute the potency of the ones I loved, or maybe Joni would go to places I could not follow her to, like encountering something about a crush that is a profound ick and finding it difficult to let it go. This happened once when I stood for the first time in the bedroom of someone I was obsessed with, and it was so fetid and disordered that the desire I'd felt evaporated immediately. And to be honest, I'd put a mental blockade on one album because it is infamous for featuring Joni in Blackface as her alter ego "Art Nouveau" on the cover. I was a coward who didn't want to complicate my relationship with her music.

The Asylum Albums(1976-1980) - four records she made with the Asylum label - have been remastered and released as a box set. It opens with her eighth studio album, the mysterious, sexy and restless Hejira, followed by the curiously free, jazz-inflected Don Juan's Reckless Daughter, then Mingus - her experimental tribute to and collaboration with Charles Mingus - and ends with her 1980 double live-album Shadows and Light. Together they document a wild travelling - and a kind of expressive unravelling - of her musical style.

For the past few weeks, I've listened to them exclusively, pushing myself beyond my pre-existing love of Hejira, which in recent years has become my late-night listen, the record I turn to for company when my vulnerability is keening for a soundtrack. On those nights I play "Coyote", "Amelia" and "Hejira" on repeat, and when there are gatherings at my flat, I ask my pal Richard - who has a beautiful counter tenor voice - to sing "Amelia" for me while we watch a YouTube video of photos of Joni and Amelia Earhart in montage. When he's done, I ask him to sing it again, which he does, and we lose our friends who take less comfort in melancholy than we do to their Ubers and night buses home.

Hejira is a strange record of land and air, the musical arrangements, the fuzz and looping rhythms of the bass and guitar, remind us we are earthbound and will kick up psychic dust as we travel; elsewhere they layer with Joni's supple voice, which swoops and soars in flight. She wavers between earth and the sky, always in motion. It remains the standout for me among these four records, forever in my personal canon of art that interrogates and valorises the experience of a woman being alone.

But if I've not quite come to love her next two albums Don Juan's Restless Daughter and Mingus, I've been grateful to spend time with them. While the songs on these records are less sticky to my ear (I can't summon them intact as I can Joni's earlier songs), I remain intrigued by them, respecting the scale of her ambition. She made what she wanted to, art before sales. She abandoned the comfort of her reputation to be "a musical student" of jazz and Charles Mingus, and arrived at something wholly unique, if not commercially viable. This creative risk-taking invigorates me.

The final record in the set, her live album Shadows and Light, features songs as early as 1970's "Woodstock" and represents 10 years of songwriting. If you were to listen to her songs chronologically, you'd get the impression of an utterly transformed artist, but hearing them performed out of sequence, with the cat-footed jazz of "The Dry Cleaner From Des Moines" followed by the reflective, resigned self-knowledge of "Amelia" somehow makes complete sense. There's coherence and cadence to be found in the collage of a setlist.

As I've been listening to each album, I've found myself reading the lyrics as I would a collection of poems. I note down lines I'm drawn to, I find motifs, patterns, incongruence. I ask myself what is this song all about? How does this song connect to the song before, the record before, the record before this record? That's the inquiry Joni's work invites; each song exists on its own terms, has its own internal coherence, but as they layer in the mind, they begin to morph, extend their boundaries, become stranger and more expansive.

Joni returns to the same themes and expressions again and again, toying with her own iconography. Addressing her lover in the song "Coyote", she tells him the Coyote she is having a dalliance with has "those same eyes - just like yours", calling back to "A Case of You" on which she tells her lover of the woman she meets who has "eyes like yours".

"Sweet Sucker Dance" brought to mind "The Last Time I Saw Richard", where cynicism and romantic desire are warring for dominance. "Amelia" and "Paprika Plains" muse on the bleak terrain of the desert and prairie. "The Silky Veils of Ardor" alludes to "River", ending with Joni singing: "I wish I had the wings/ Of Noah's pretty little white dove/ So I could fly this raging river." She is seemingly always wanting to escape, even if that escape route changes into something darker: Blue ends with Joni wishing to emerge from her cocoon into a butterfly with gorgeous wings; Hejira leaves us with the image of Joni as "a black crow flying/ in a blue sky".

Over the course of her Asylum years, if Joni becomes more unpredictable in musical terms (listening to Don Juan's Restless Daughter and Mingus I'd sometimes find myself braced for what she might do next; these records are full of improvisational swerves), she does maintain a fidelity to her chief subject, which I've come to understand as uncertainty. Should she leave or stay? Can she be free if others are not? Should she pursue noble causes or give in to her desires? Perhaps this is why I've found listening to these records so affecting. Hejira is the most musically stable, but even in those songs she creates a sense of giving way, rhythmically and sonically, falling back on herself like trying to walk on a fine-sand beach. The musical qualities match the lyrical ones. They are in balance.

I realise I've fallen into the trap of building a relationship with these records based on my relationship to Blue, like how a friend met through a friend becomes tethered to the first friendship - a person seen through another person - until that friendship matures and becomes its own unique relationship. I hear Blue's long echo across all four records, its lyrical ambivalence and impatience for moving on and staying put, the grounding plains and wild skies, the fluid but searching directions of Joni's sonic world. If she can't shake off her emotional and intellectual relationship with ambivalence, she's still travelling far and wide. I find myself wanting to match her pace, to move with her into a new decade, eager to know her music beyond the Asylum years.