In Joanne Robertson’s oil paintings, thick knots of red and brown often appear in the lower left-hand corner. They push back against the sloshes of pale color as a visual analogue for how her music works. Those reds and browns are like the rhythmic unrest at the heart of her serene songs, where melodies twist and buckle and collapse. And like her frequent collaborator Dean Blunt, Robertson’s visual practice bleeds into her music, shaping its tension and motion. She wanders with supple precision across both canvas and song in an improvisatory state, but it’s in music that she comes closest to the divine.

Blurrr, Robertson’s sixth solo album and her undisputed masterpiece, is at points so beautiful—53 seconds into “Always Were,” to be exact, or four minutes, 31 seconds into “Peaceful”—that it feels difficult to breathe alongside it. Here, Robertson sounds as though she has reached a stratosphere where the soul can stretch its legs and roam more freely. It is scarcely conceivable that Robertson recorded the album within the confines of a room, constructed from earthly material, somewhere inside a city. For its nearly 45-minute duration, there is only this.

The sound of Blurrr might best be likened to the Cocteau Twins calling from inside the house: a lo-fi rendering of the band’s beautiful slurry. Like Elizabeth Fraser, Robertson makes a voice feel much larger than the words it carries, though she isn’t singing with an alien tongue so much as blurring words into tonal brushstrokes. If Fraser’s gift was a kind of ecstatic, non-linguistic invention, Robertson’s errs closer to meaning. Her lyrics hover just beyond grasp, vaguely intelligible but never fully yielded. Grouper is another obvious point of comparison: both artists summon an immense solitude, with melodies and lyrics that seem dredged from half-buried incidents and associations, as if carried across remote distances and centuries before reaching us. Robertson, though, gathers those fragments into her voice, which doesn’t just bear them forward but distills them; purified in the very act of singing.

On tracks like “Gown,” where she fully opens her melodic range, her voice is all yearning and suffering. Even in moments when her phrasing feels more provisional and hesitant, as on “Ghost,” it sounds as if she is attempting to stake a claim on the infinite. Her voice and guitar zigzag around one another, rarely colliding into melodic symmetry. Her voice the blur, her guitar the furious red and brown tangles; never just a scaffold but a tactile object that thuds with wood and wire, each string caught mid-rattle, harmonics clanging.

Robertson’s music is always in conversation with itself. She responds to her own sounds—and to the energies they draw out of her—in real time, lingering on particularly beautiful lines of open-tuned guitar for several beats beyond the measure, or indulging in vocal curlicues that seem as pleasurable to sing as they are to hear. She is, as her friend Derek Bailey once suggested of the ‘freest’ improvisers, still in dialogue with some prior tradition. For Robertson, that tradition is free jazz, a practice that has inspired both her painting and music. Not its atonality, but its insistence on dialogue. Like Cecil Taylor’s loose figurations, which cohered through rhythm and energy rather than fixed harmony, her songs are less compositions than nerve-first zones of encounter. They have always been journeys in that sense, but where her earliest recordings could sprawl into unwieldiness, Blurrr feels propelled, as if moving toward a destination that never quite arrives but always draws you forward.

Blurrr is, above all, a lonely record. Even more than on previous albums, Robertson sounds as though she has been left in a room long enough to forget anyone else’s presence, her voice and guitar carrying that sense of solitude in every phrase. She captures the unfiltered hum of consciousness, as though she were setting the colors of a brain scan to melody. Across the album, solitude and disinhibition are the same gesture: the absence of an audience becomes the condition for the most audacious wandering.

On the back half of the album, cellist Oliver Coates follows Robertson down into her solitude and draws out the immensity that the earlier songs had only shyly hinted at. The retentive tones Coates and Robertson form together are, in the strictest sense, heaven. Coates gives Robertson’s songs a larger wingspan, tracing fine lines around Robertson’s watercolor suggestions and flying them to their full, magisterial potential. His lovely melodies seize and carry. It is a gift to hear Coates so sentimental, as though he truly understands the inner grandeur of Robertson’s work. This requires no primness, no cool detachment, nothing remotely aslant; only a very direct channel of feeling.

By each track’s end, we don’t so much see Robertson any clearer than we do the latent ideas and feelings that animate her: tragedy, ecstasy, doom. “Mystery gone into-wait take it with you,” she sings on ‘Gown’. On the page, it barely registers; sung, it strikes hard. And then the silence that follows it feels far heavier than the one before. Blurrr is an epic drawn in miniature. You take it with you.