‘When the Stars Begin to Fall’, Studio Museum, Harlem, New York

For America’s black artists, the South is a cruel and holy land. It is where flavours are strongest and the blues are sweetest, where religion is most sincere. It is a place of nostalgia, even for those who were born a thousand miles away. That, at any rate, is the premise that holds together – sort of – a bracing exhibition at the Studio Museum in Harlem, New York, called When the Stars Begin to Fall: Imagination and the American South.

To make his point, curator Thomas Lax has assembled a disparate jumble of materials, from the vibrant work of self-taught folk artists in the rural South to the more cramped and self-conscious creations of professionals with graduate degrees and gallery representation. The show helps explain why the credentialed members of the Southern diaspora find the visionary, vernacular eccentrics so fascinating: because they envy their visceral immediacy and compulsive drama.

Lax has stacked the deck: although he has brought in establishment figures such as Carrie Mae Weems and Kerry James Marshall, too often the sculptures, drawings and assemblages of the self-taught manage to trump the polished products of their more educated colleagues.

Right at the start, we’re confronted with a set of drawings by JB Murray, an illiterate Georgia farmer whose vision of God inspired him to pick up a pen at age 70, and a sculpture by Houston-based art school grad Trenton Doyle Hancock, whose work has appeared in two Whitney Biennials. Murray wrote in a dialect that he described as “the language of the Holy Spirit, direct from God”, covering thousands of sheets in indecipherable script intermingled with abstract purple splodges. This powerful conflation of word and image overflows with expressive intensity, even if the precise meaning remains out of reach. The calligraphy, etched with the force of a divine breath, amplifies his otherworldly memos. The force of his mark betrays the compulsion to create.

Hancock’s long “Vegan Arm”, on the other hand, trembles with self-consciousness. A knobby limb reaches out of the wall and dangles a steel bucket that’s filled with a viscous pink liquid, like a dinosaur’s dose of Pepto-Bismol. Hancock, a minister’s stepson, has offered possible interpretations – suggesting, for instance, that the arm might be “fishing for souls” or “taking in” the liquid, as at an altar. Whatever the profundity of his intentions, the result is slick and market-ready, cloaked in prophylactic irony. Compared with Murray’s inscrutable messages, Hancock’s professed spirituality feels inert.

It was surely not Lax’s intention to promote the aesthetic virtues of mental illness, incarceration and isolation, but he winds up making a powerful case for them nevertheless. Patricia Satterwhite, a 63-year-old schizophrenic resident of Columbia, South Carolina, hasn’t left her home in 10 years – yet the vistas she has beheld on home-shopping TV shows have inspired her to draw with primal urgency. She imagines the products that the cable channels fail to offer: a diamond-studded picket fence, a portable fireplace, a chair with a built-in CD shelf, a globular lamp that looks vaguely like a human head – all meticulously diagrammed and pithily captioned. These drawings are a way for Satterwhite to burst out of her solitude and connect.

Most poignant of all are the sketches appearing below the phrase “How lovely is me being as I am”. These are dense, compacted abstractions, shapes whose meaning remains opaque even as the desire to communicate feels palpable. “Her drawings are made from necessity,” says her son Jacolby Satterwhite. “They are direct, specific, original and sincere.”

The younger Satterwhite is an artist too, though of an utterly different stripe. He lives in New York, has collaborated with Jay-Z and wields a toolbox that includes cyborg avatars and live marathon dance sessions. Here, he collaborates with his most loyal partner: Mom. Translating his mother’s low-tech drawings into luminous 3D, he incorporates them in a psychedelic wallpaper. It’s a touching homage, but the son has borrowed more from the mother than he is able to repay.

Equally spellbinding in their morbid showmanship are the busts that the late gravedigger and blues-master James “Son” Thomas sculpted out of unfired clay from the Yazoo River in Mississippi. Thomas fitted out his eerie effigies with human hair and rows of real teeth, adding a pair of sunglasses to one skull and earrings to another. This roguish suite evokes an early stage in the cycle of death, before decay has obliterated flesh. It’s hard to tell if they’re memorials for real people or fictional portraits, but either way they suggest that regardless of race, sex, age or creed, none of us winds up pretty. “A skull has got to be ugly,” Thomas said, “because it’s nothing but bones and teeth.”

In this awkward meeting of the homespun and the rarefied, a few artists – notably John Outterbridge – manage to repurpose vernacular techniques to deal with complex ideas and sophisticated aesthetics. Outterbridge was born in Greenville, North Carolina and grew up amid handmade buckets, colourful pitchers and fences encrusted with seashells. Then he went to art school in Chicago, moved to Los Angeles, and met eminences such as Robert Rauschenberg. But along the way he had learned to discard nothing – certainly not the past. In LA’s riot-plagued neighbourhood of Watts, he scavenged in the rubble, alchemising the shards he found there into secular altarpieces.

One spectacular untitled piece from the 1970s consists of a bulbous female figure without head or arms. Outterbridge has tried to salve her wounds, wrapping a torn bandage around the knee, capping the stumps in leather and metal, and armouring her privates with a steel bikini. But the body remains funny and horrifying, an ode to ungainly beauty. This faceless grotesque could be the exhibition’s muse, mutely embodying Outterbridge’s recent reflection: “Sometimes you ask yourself, ‘What is art? And what do I care what it is called and what it becomes?’ The only thing I know about it is that sometimes it has a tendency to shake me up and to shake what is around me up.” It’s that “sometimes” that forms the exhibition’s real dividing line – between dispassionate commentary and soul-rattling source.

‘When the Stars Begin to Fall’, Studio Museum, Harlem, New York, until June 29, studiomuseum.org