In December 1971, a man at the exit of the Museum of Modern Art had a question for departing visitors: “What did you think of the Yoko Ono exhibition?”

Some were confused (“What exhibition?”), others irritated (“I couldn’t find it!”) or delighted (“Well I just thought it was amazing”). To a man who had trouble locating the show, the interviewer conceded, “It’s here, it’s just mostly in people’s minds.”

The man nodded. “Yes,” he said, “I thought that might be the case.”

These were some of the reactions to Ono’s “Museum of Modern (F)art,” a self-appointed MoMA debut, staged without the museum’s permission. She published a catalog, placed ads in The Village Voice and inserted a sign at the museum entrance stating that hundreds of perfume-soaked flies had been released inside. It was up to visitors to find them, the notice said, perhaps by following the errant wafts of fragrance drifting past the Pollocks, Picassos or Van Goghs.

More than 50 years later, the Tokyo-born artist known for her marriage to John Lennon as much as her avant-garde (and often very funny) art has a much-anticipated retrospective at Tate Modern in London, running through Sept. 1. The show, “Yoko Ono: Music of the Mind,” contains more than 200 works spanning seven decades. Like “Museum of Modern (F)art,” which is part of the retrospective, most of those works are in people’s minds.

The exhibition takes us through Ono’s work and life chronologically. The first space immediately establishes the sense of spare elegance that dominates the artist’s oeuvre, which unfolds across performance, installation, film, text, sound and sculpture.

Like many of the works in the show, “Lighting Piece” is presented in multiple iterations. It is one of her earliest “instruction pieces”: a small typewritten card, dated “autumn 1955,” and affixed to the wall. It reads, “Light a match and watch till it goes out.”

Nearby, three photographs show Ono doing just that, while sitting at a grand piano onstage, in 1962. Projected on another wall is a 1966 filmed version of the same instruction. We see the flickering flame, shot with a high-speed camera and then played back at a standard speed, waning at an impossibly slow rate. It exists across time and space and you, too, are invited to watch it die today, tomorrow, whenever.

Born in 1933, Ono grew up in wartime and postwar Japan. It might be easy to link the austerity of her work to a childhood marked by scarcity, homelessness and mass destruction. “Those experiences of the early days cast a long shadow in my life,” the artist has said, recalling how she and her brother, displaced and hungry in the Japanese countryside, would look up at the sky and imagine menus filled with delicious meals that they could not eat.

Perhaps this epicurean fantasy was one Ono’s first instruction pieces, but from early on, her work was also shaped by a sophisticated educational background: She was the first female philosophy student at Gakushuin University in Tokyo, then studied poetry and musical composition at Sarah Lawrence after she moved to New York in 1953.

Ono quickly fell in with the city’s most admired experimental musicians and performance artists of the time, including John Cage, La Monte Young and George Maciunas — the father of the Fluxus movement, which emphasized how art could be made by anyone and happen anywhere.

In the retrospective, the decade after her arrival in New York is largely represented by documentation of performances in loft spaces and galleries, and later onstage, also in Tokyo, where she returned from 1962-64.

Two “Instruction Paintings” are examples of interactive works from 1961, in which the title tells us what to do. “Painting to Be Stepped On,” for example, is just what it sounds like — a geometric cutout of canvas stuck to the floor — and shows Ono’s embrace of the idea that art is live rather than static and relies on audience participation. This is encouraged throughout the exhibition, which invites visitors to follow various instructions: draw your shadow, shake hands through a hole in a canvas, imagine a painting in your head.

In no work is this more striking and unsettling than in “Cut Piece” (1964), one of the most powerful performance pieces of the 20th century. In a 1965 version, filmed at Carnegie Hall by the Maysles brothers, Ono kneels onstage in her best suit and invites audience members to cut away pieces of her clothes.

While some are modest in their takings, the same man approaches twice — once cutting a hole in her shirt so that her breast pokes through, and later gleefully removing the top half of her slip and cutting the straps of her brassiere beneath. Ono sits motionless and passive — though a few vague eye rolls provide relief — while the audience takes what it wants from her without protest.

The following year, Ono traveled to London and the rest, as they say, is history. Performances gave way to sculptural installations of white chess sets, rooms of objects cut in two, apples on transparent plinths and mirrored boxes that reflect the smile of whomever opens them.

“Film No. 4 (‘BOTTOMS’)” (1966-67) is a veritable who’s who of London’s alternative art scene via their naked derrières in motion. The simple film seems silly, but is also mesmerizing and anarchic: “an aimless petition signed by people with their anuses,” according to Ono. (It was banned by the British Board of Film Censors.)

Ono met Lennon at one of her openings. It was the beginning of an artistic collaboration frequently dismissed as pop celebrity high jinks or derided in sexist and racist terms. (No, Ono was not an interloper who destroyed The Beatles, etc.)

Later work sits uneasily between high and low registers, conceptual installation and mainstream media intervention. (In 1982, she placed an ad in The New York Times calling for peace.) The evocative koan-like poetry of her earlier scores — “watch the sun until it becomes square,” “give moving announcement each time you die” — becomes simplistic statements: “Take a piece of the sky. Know that we are all part of each other,” “IMAGINE PEACE,” “PEACE is POWER.”

At the end of the exhibition you are invited to write a wish on a white card and affix it to a potted olive tree. Is wishing enough? Can we imagine peace? At first I was cynically uneasy about the lack of “art” in later text works. But Ono’s instructions are not as straightforward as they seem, and they require some faith in other people. What did I think of the Yoko Ono exhibition? What did you think?

Yoko Ono: Music of the Mind
Through Sept. 1 at Tate Modern in London; tate.org.uk.