I always wondered about Senga Nengudi. She's a legend for her 1970s sculptures made of pantyhose, but art history had her filed as a one-hit wonder.

True: What a hit. There's a fever and music to her sculptures made of pantyhose stretched and pulled between the wall and the floor. As majestic and abstract as they are, they also make an ache rise in my lower back, my legs, my crotch. When I confront them, I hear my mother's worried and worrisome words to me as a feisty teenager: Cross your legs. I see the flashing slogan: "Control Top." My body has not been the same size throughout my life, and that has mattered very much. I do not conquer these things, never will. These things hit deep.

I've loved Nengudi's sculptures. Over the years, I've seen them the way they usually appear—placed in line in the chronological march through 20th-century art history at major museums from New York to Paris—next to Robert Morris's sagging rubber sculptures and Eva Hesse's deteriorating latex, all representing a thing called postminimalism.

Now I realize how feeble my love was.

Senga Nengudi: Improvisational Gestures, the survey exhibition at the Henry Art Gallery with 14 of her sculptures plus photographs, videos, and a performance, reveals to me that I didn't really know the first thing about her work.

"I never had a dancer's body," Nengudi intoned, adding a British accent to the word "dancer"—dONcer—as she spoke to an audience at the Henry last weekend.

She is a dancer, but what she means is that dance where the size and shape of the body matters is not her kind of dance. Her sculptures don't even stay the same size throughout a single exhibition: They stretch slightly, sag. If you were to take a measurement of them on opening and closing nights, you would see that they literally show their age. She replaces the hose as necessary and provides instructions to museums for how the forms are created. So they're never exactly the same twice.

And she is not exactly a sculptor. Even the sculptures are meant to be what she calls "activated" by performers. In photographs and videos, Nengudi demonstrates that her work is not kin to postminimalism so much as Brazilian body art of the 1970s, African ceremonial ritual, African American modern dance. She loved Allan Kaprow's formless, improvisational 1960s Happenings, when artworks were left open for audiences to explore, to play with physically.

She never acknowledged limits on what she could make. When she noticed that a Catholic girls' school was being demolished in Los Angeles in 1980, she ran onto the site with the bulldozers rolling behind her and enacted a version of Rapunzel in ruins. All that's visible in Barbara McCullough's resulting photograph are a pair of pantyhose (worn on Nengudi's head, but the crouching artist is unseen) stretched from the brick school's one remaining window down into the rubble of the ground.

In 2007, Nengudi took her video camera into a textile mill in New York. She created a film she titled The Threader, following a man named Amer Baig as he worked to make silk drapery cord. His rapid motions are bewildering and spellbinding. They are dance, performance, sculpture, and labor all in one.

A room-sized installation from that time, Warp Trance, is also at the Henry.

You walk into a darkened room to find a spectacle. Moving lights crawl across the walls and floor in patterns, like moving traffic or computer code scrolling down a screen.

The light patterns are created by video projected onto the patterned holes in strung-up rolls (like venetian blinds) of Jacquard punch cards. When these paper cards with holes punched out were invented, they revolutionized the production of textiles. The holes told the machines what to do. Now Jacquard punch cards are seen as the earliest predecessor to computer programming. Here, removed from function, they are naked, ancient, and reborn. You bathe in Warp Trance.

I can't stop thinking about one performance Nengudi staged under an LA freeway in 1978. Its participants were the members of a loose collective of Black men and women artists called Studio Z. It included people who would become influential in their own right, such as David Hammons and Maren Hassinger.

But the costumes they wore to perform improvised movement and music—captured in color photographs—were made of throwaway materials. As disposable people in the eyes of a white supremacist society, they chose a throwaway location, too, on that patchy ground under the concrete overpass.

The videographer's camera conked out that day. It's difficult to make out the movement in still photographs. But in the catalog for the exhibition, I learned that Nengudi was responding to a specific situation: a rift between Black men and women because mainstream feminism didn't advocate for the issues of Black women, and Black Power asked women to take a backseat.

Nengudi's goal was togetherness.

Seeing more of Nengudi's pantyhose sculptures, it's obvious that they're not just about female bodies. Black female bodies are the common denominator, the base of operations. But the sculptures conjoin a people divided by gender constructs and biologies. In a single sculpture, I might see in the knotted, dangling, bulbous nylons both penises at rest and post-nursing breasts. Nengudi may have begun the sculptures when her children were born, but she has continued, and they have become multifarious. Formally and emotionally, there is no "typical" pantyhose piece, unlike the idea I'd had in my mind from seeing them one at a time. They can be playful, agonized, confused, hopeful, tired, or furious, the nylon mesh stretched, twisted, tied, cut, balled up, pressed flat, stuffed, flying upward, weighted down.

I'd also never paid much mind to the fact that the pantyhose series is titled R.S.V.P., or "please respond."

"Can everyone stand up, please."

That's how Nengudi began her artist talk—with a request. We'd all just watched Joseph "jo" Blake and Haruko Crow Nishimura "activate" an R.S.V.P. piece in the gallery involving five pairs of pantyhose. The dancers lived whole lives in those 15 minutes with the sculpture, like the characters in an August Wilson play, finding joy, desperation, collapse, wishing, protecting.

Now we in the auditorium were being asked to please respond to the performance in a single improvised movement each.

The first man to go, an older white man in the front row, put his hands in the air and fell to the floor. Nervous laughter.

It was the end of a week of bodies dropping, actually falling dead, over the state of race in America, which Nengudi would allude to later in her talk, at which point she would ask us to draw one thing humans all have in common, in a beautifully 1970s moment.

But we were still in the procession of shimmies, elaborate arm waves, self-hugs, and even one hostile shrug. At some point, I noticed that Nengudi, onstage, was repeating every person's movement, conducting wordless individual conversations lasting a few heightened seconds each. She took each body into her body, and gave us back anew. I know now. That is what her art does.