Rites of Passage review: stilt-walkers and slave ship ghosts brave the Atlantic

“I am here because you were there,” reads the black neon sign, glowing bleakly. It quotes the now shadow foreign secretary, David Lammy, from an impassioned 2018 speech in response to the Windrush scandal. The neon, by Southend-based artist Elsa James, hangs over the entrance to Rites of Passage, a group exhibition of 19 black artists who all, in different ways, have their own stories and histories of migration. Set against strong blue walls, this is one of those one-thing-after-another shows in which disparities of scale, medium, subject matter, intention and artistic language are so varied it is hard to make sense of it all. Lammy’s quotation is succinct, direct and so freighted that the rest of the show finds it hard to keep up the pace, let alone the focus.

Patrick Quarm’s painted portraits are strange hybrids, between realist and fantastical. Quarm’s figures – all friends or family of the US-based Ghanaian artist – pose as though for formal portraits, yet their skin and faces as well as their clothes are often patterned with dizzying wax-print fabric designs. Even the backgrounds are covered in yet more pattern and hot colour. These unstretched images are held out from the gallery wall by life-sized resin arms and hands, which proffer them to us. Painted limbs intrude in the pictures, too, covering the sitters’ mouths, ears and eyes. This game of see no evil, speak no evil, provides further complication. It all feels overdetermined and overcooked.

Nearby, a small, single painting by Sahara Longe depicts a lonesome, pallid, nude man (if it is a man) standing in the background, looking vulnerable. In the foreground, a black woman has an implacable look. It is as if I’ve blundered into a situation I’m not supposed to witness. I wonder what the story is, more than I do with any of Quarm’s works.

This low-key, deceptively simple scene makes way for a series of photos by Àsìkò, a London-born photographer of Nigerian Yoruba heritage. A group of traditionally costumed, masked dancers are engaged in some ritual pursuit in a series of staged images. On hidden stilts beneath their costumes, these oddly elongated beings stalk about a familiar and rain-sodden English seaside town, looming over the holiday homes and standing on pointe, like ballet dancers, at the roadside.

Curator Péjú Oshin highlights the “triple consciousness experienced by members of the African diaspora when encountering counterparts who identify with local majority populations”. The themes of Rites of Passage also include the communal rituals that attend significant moments in a life, but these are only fitfully explored. Alexandria Smith, an American artist who runs the Royal College of Art’s painting course, makes cartoonish, goofily surreal painted assemblages. Two naked bodies (or is it one body, repeated?) collide in a joyous dance, their heads morphing into a single cloud of hair. Smith’s paintings have an Afrofuturistic, early 1970s album-cover feel.

In another work a sort of altar stands in the foreground. A frozen fire burns on it. Black stuff drools from beneath the flames. An armless naked female figure with large nipples and a one-eyed blob for a head stands on one leg in the desert, or possibly the sea. Low mountains saw-tooth the horizon under a grey sky. The bottom half of a female body, white legs bent, rests on a low platform nearby.

Something terrible has happened here: there’s just an oozing, gory crimson glob where the rest of the body should be. Is this some awful disembowelment, or a sci-fi horror parasitic birth? Is this glob flesh or fungus? Ayesha Feisal’s title, Rooted (Infinite Source) points in a possibly less gruesome direction, but it is impossible to know. The evident care and loving attention the making of this sculpture entailed makes the image even more peculiar. Are we witnessing a birth?

On a canvas across the room, little ceramic flowers burst like pustules from a deep-bass sludge of painted abstract riffs, riven by slivers of sizzling metallic paint and occasional written phrases, which emerge from the mix like snatches of half-heard lyrics. “You may blame Aphrodite but I can only blame you”, “face beat so sweet” and “No flaws”. Michaela Yearwood-Dan’s Final Track (we can do it real big)is like a painted equivalent to a heavily mixed dub record.

Nengi Omuku paints scenes on woven-together strips of a traditional Nigerian fabric. Striped cloth, drying on a line and laid out on a beach, also appears in one painting. In another, fishermen haul a net. Other figures appear and disappear, floating and dissolving. There is a real feeling of a world remembered, of drifting and daydreaming and losing oneself.

Stretched and torn and knotted tights, crocheted and braided cotton yarn and thread, with ad hoc repairs and spidery drawing, climb over a wooden frame in a work by Enam Gbewonyo. The title, Colonialist Ravelry, An Infection of Mind, Skin and Being. Blackness Hangs on a Determined Survival!, is as tangled and knotty as the work itself. Gbewonyo also uses these materials in performances. Picking and cutting, doing and undoing and redoing, braiding and knotting and joining are more than just technique here; this is process as metaphor.

In a darkened room, voices sing and chant. In Victor Ehikhamenor’s Do This in Memory of Us a diagramatic image of a slave ship’s deck, detailing the disposition of its human cargo, is suspended from the ceiling and reflected in a mirrored floor at our feet. The sound seems to be a funeral service, and the image itself is made from rosary beads, with their little brightly glinting hanging crosses, threaded on to lace and canvas. Rite of passage here becomes the middle passage, the crossing of the Atlantic to the Americas.

Returning to the beginning, and beyond the neon of Lammy’s speech, a fishing net is stretched floor to ceiling in a small room. On the other side of the net a two-screen digital film shows a pair of costumed and masked figures turning in a slow, mesmerising dance, by Julianknxx. The dancers turn in circles and disappear in a fog of dry ice. And then they’re back again, in an endless loop. Knxx is from Sierra Leone, and this invocation of his heritage is also a repeated gesture of departure and return. Sierra Leone was a major departure point for the slave ships to the Americas, and from 1787 Freetown also became a point of repatriation for freed slaves. I just wish Rites of Passage were always so focused.

• Rites of Passage is at Gagosian Britannia Street, London, until 29 April