The credits for Solange Knowles’ fourth album are long and impressively varied, offering up a supporting cast that includes everyone from Pharrell Williams to John Carroll Kirby – a new age-y ambient artist given to releasing albums called things like Meditations in Music – Gucci Mane to actor Debbie Allen. Those old enough to remember the early 80s may recall Allen sternly informing Bruno, Doris, Leroy et al that “Right here’s where you start paying … in sweat” every week during the intro to Fame on BBC One. One track alone features a group of backing singers involving Tyler, the Creator, Panda Bear from Animal Collective and Sampha, which, by anyone’s standards, seems a fairly eclectic crowd to herd into a vocal booth.

But one credit sticks out, because you see it over and over again: “All lyrics and melodies written by Solange Knowles.” In a pop landscape where even confessional singer-songwriters require a team of co-authors in order to bare their souls, here is evidence that Knowles is cut from a slightly different, more auteur-like cloth. No assistance is required from blue-chip LA writing teams, former indie stars turned hacks for hire, or shadowy pop factories whose presence makes your songwriting credits look like the starting 11 of the Swedish World Cup squad.

Mood piece ... When I Get Home album artwork.

Knowles has thus far triumphed against the odds by doing her own thing. Life is seldom kind to younger siblings of superstars who enter the business – they’re almost invariably doomed to toil in their shadow – but Beyoncé’s younger sister has succeeded in establishing herself as an entirely separate entity: weirder, artier, more given to staging interdisciplinary performance art pieces at museums and galleries than blockbusting record-breaking world tours. Certainly, no one who listens to When I Get Home is going to confuse it with a rapacious grab for mainstream success. What initially sounds like an impressionistic intro piece, Things I Imagined, is gradually revealed to set out the album’s stylistic stall: an electric piano plays jazzy chord changes, the time signature shifts unexpectedly, Knowles repeats the title over and over, the vocal melody mutating, vintage synthesisers float and burble, and the whole thing doesn’t so much end as unravel and peter out. It’s both very beautiful and very hazy.

The latter becomes a problem as the album progresses. The songs frequently sound like jams or extemporisations on a theme, where melodies float away vaporously or get stuck in repetition. The strident call for “black faith” in Almeda aside, the lyrics are similarly vague, often centring on a couple of recurring phrases. There are absolutely exquisite moments: the thrillingly chaotic way Almeda crashes into life, as if someone’s pressed record in the middle of a performance; the dubby strangeness of Sound of Rain; the stoned, piano and synth sprawl that constitutes Down With the Clique’s backing track. But despite the fact that virtually everything lasts less than three minutes, there’s a sense that the tracks are rambling on a little.

Melody mutating ... Solange at Glastonbury in 2017. Photograph: Samir Hussein/Redferns

Way to the Show starts out fantastically, with Knowles’ vocals floating over gloopy electronics and a stammering rhythm, an off-kilter take on an early 90s R&B slow jam. But when it becomes apparent that this is it, and it’s not building up to a sparkling chorus, it’s hard to suppress a feeling of being slightly underwhelmed. It’s a situation compounded by Jerrod, the most straightforward thing here, where the fogginess clears: the chord changes are still unexpected, the sound remains in an intriguing space between smooth, jazzy late 70s/early 80s soul and something more left-field and futuristic, but there’s an indisputably great melody attached. You listen and think would it have killed you to write a few more of these?

Evidently Knowles didn’t want to. On one level, there’s nothing half-formed about When I Get Home at all: it’s self-evidently the work of an artist with a clear musical concept. You can tell by the way the guest stars and famous co-producers don’t impose themselves on proceedings at all – most of the time, you barely notice they’re there, so subservient are their talents to Knowles’ overall vision. And as a mood piece, an ambient album, When I Get Home works really well. Its sound is enveloping and frequently lovely, and the songs and interludes wash subtly over each other. There are lots of intriguing ideas here, and it might be better thought of as one long fragmentary track than a collection of songs. But it’s an album that feels like it’s hovering rather than actually heading anywhere, diverting rather than impactful.