Back at MoMA, Mr. Cherix explained that one of the few Fluxus works the museum did acquire, early on, was a book by Ms. Ono called “Grapefruit,” published in 1964. It is a kind of how-to guide for her art, presenting “instructions” for many of the works she will be showing at MoMA — “Painting to Be Stepped On” (“leave a piece of canvas or finished painting on the floor”), “Touch Poem for a Group of People” (“touch each other,” as visitors will do in a designated space at MoMA) and, of course, “Smoke Piece” (“light canvas or any finished painting with a cigarette at any time for any length of time”). These get at Ms. Ono’s major artistic concept: the idea that works of art can be conceived as written “scores” to be realized later, whether by the artist herself or someone else — or that exist only as pure, blue-sky ideas. She feels that’s a model for how we realize any change in the world. “We visualize it, imagine it, and think that it’s not going to happen — and it’s happening,” Ms. Ono said.

Another inspiration for the new Ono project, Mr. Cherix said, was a 1971 “intervention” that the artist staged at MoMA, without the museum’s permission, to which she gave the puckish title of “Yoko Ono — One Woman Show” (yes, that’s also in the title of the new exhibition). Ms. Ono’s guerrilla contribution to MoMA’s program that year took the form of revealing (falsely) that she had released an army of flies around the museum, as a kind of Fluxus fifth column. For the card announcing her fictional show, she retouched a photo of the museum’s signage to insert a naughty letter “f” before its final word, thus creating the “Museum of Modern (f)Art.”

“I did a conceptual show and that was it, for me,” said Ms. Ono, never expecting her fictional solo exhibition to become reality. But now, 44 years later, she’s getting precisely the retrospective MoMA could have given her back then, according to Mr. Biesenbach, if it had been up to speed. His interest in the history of performance art and his long connection to Ms. Ono — she was in one of his first notable projects, in Berlin in 1992 — coupled with Mr. Cherix’s key role in acquiring a major Fluxus collection in 2008, made it seem natural to approach Ms. Ono with the idea for their show. At first she was more keen on current projects than revisiting the past, she said, but her trust in MoMA’s pair of “incredibly sensitive” curators changed her mind.