Choreographer Merce Cunningham famously prided himself on making artistic decisions based on chance, sometimes even just before curtain. By contrast, “Common Time,” Walker Art Center’s astounding, expansive exhibition connecting Cunningham and his artistic collaborators, was years in the making.

Curators spent many hours mulling how to represent dance, costumes, set decor and music in a gallery setting. Their greatest accomplishment is never, in all their attentive micro-planning, losing sight of the spontaneous energy that epitomized Cunningham and his nearly 70-year career.

They recognized that even though the collection includes a treasure trove of video, reuniting some of his dancers for live performances would be vital to the exhibit’s success. Four were in the galleries for the grand opening Wednesday and Thursday, dancing for an audience of critics, music fans and art lovers from around the country.

“Common Time” is the largest display of Cunningham-related art that the Walker has put on public view since acquiring the choreographer’s collection in 2011.

When Cunningham died at age 90 in 2009, he left behind a detailed plan for preserving his dances and disbanding his company after a legacy tour. He did not, however, specify the landing spot for the company’s ephemera, including sets and costumes by boldfaced art-world names like Andy Warhol, Jasper Johns and Robert Rauschenberg.

Although the Walker has not shared the purchase price, its prospects were bolstered by its long-standing relationship with the Cunningham company, which dates to 1963, when the troupe was more a less a handful of dancers road-tripping in a van, with a set by Rauschenberg strapped on top and a soon-to-be famous composer named John Cage riding shotgun.

Cunningham was an egoless impresario who didn’t own a tux. That’s obvious from the very first gallery that Walker visitors enter. To the left is a video of Cunningham performing “Changling,” a 1957 solo he created by listing all the movements he could perform with each limb, then putting them in order using chance processes. The tattered red wool body suit and felt skull cap he wore are front and center, and in the next room, there is a rather garish red-and-pink sculptural “combine” that Rauschenberg created especially for the top of that van.

This is not an exhibition that will bowl viewers over with its beauty. A 2013 Ballets Russes retrospective featuring music, sets and costumes, presented by the National Gallery of Art and Victoria and Albert Museum, had that advantage; Matisse and Debussy are more conventional draws than Isamu Noguchi and David Tudor.

Hard-core fans of the 20th-century avant garde will want to spend hours at the Walker listening to music — there are side rooms dedicated to Tudor and Cunningham’s life partner, Cage — and watching dance films — one breathtaking gallery features more than a dozen screens. But there is also plenty here for neophytes and even families.

Kids won’t care who Warhol is while they punch silver mylar pillows that the Campbell-soup-can artist created as set pieces in 1968, nor does one need a concept of abstract expressionism to marvel at the mannequins wearing Johns’ 1970 rainbow-hued leotards for “Second Hand.”

Much later in his career, Cunningham would be able to clad his dancers in all sorts of space-agey-looking spandex. My chief concern with “Common Time” is that, although wide-ranging in concept, it focuses mostly on the choreographer’s first two decades, from the troupe’s founding at a North Carolina retreat in 1953 through the Pop Art 1970s. If you walk in not knowing Cunningham, you won’t walk out knowing that in his final decade, he had his dancers flip a coin before shows to determine whether they’d dance to commissioned scores by Radiohead or Sigur Rós (“Split Sides”) and even experimented with passing out iPods to his audience (“eyeSpace”).

There is just one way to connect with the choreographer who was still making work eight years ago, and that is to catch a performance by four of the last dancers he chose for his company.

Dylan Crossman, Silas Riener, Jamie Scott and Melissa Toogood reunited Wednesday and Thursday to stage an “Event,” a 30-minute assemblage of Cunningham’s choreography arranged for the occasion by former dancer Andrea Weber. (Two more “Events” are planned for March and April.) Patrons sat waiting in cathedral-like silence to be taken to the church of Cunningham and got the awe-struck performance they came for.

Local vocalist Mankwe Ndosi and upright bassist Nick Gaudette debuted a score worthy of Cage and his frequent collaborator, the late soprano Cathy Berberian. Although hearing the music for the first time, the dancers almost flawlessly executed their tiptoe balances, lifts and modified balletic solos. Their faces were expressionless, as Cunningham preferred. When they finished, there was thunderous applause, followed by a speech from Walker performing arts curator Philip Bither, but his attempt to thank donors was interrupted by a cacophony just outside the gallery.

It was Weber and the exuberant dancers, cheering. Cheering for themselves, for the Walker and for Cunningham.