Workers install a Yoko Ono mural on the exterior of Union Market. The mural is a collaboration between the market and the Hirshhorn Museum. (Photo by Emma McAlary)

Four works has turned into five.

“Four Works for Washington and the World,” the Hirshhorn Museum’s summer celebration of Yoko Ono, expands to five with Friday’s debut of a large-scale public art work at Union Market.

The conceptual work — “Relax. Your heart is stronger than what you think!” — is being installed this week on an exterior wall of the market at 6th Street NE. It appears in time for the final weekend of the “Four Works” exhibition at the Smithsonian’s modern and contemporary art museum on the Mall.

The public art work, which will be on view for at least three months, marks the first effort in the Hirshhorn’s new program to exhibit contemporary art in the city’s communities. Ono is the perfect artist to launch the “Hirshhorn in the City” program, said director Melissa Chiu. Union Market has hosted artists-in-residence, public art projects and studio tours, making it a natural partner for the project.

“Yoko Ono is such a major cultural icon, and she’s an artist whose work sits very well outside the museum context,” Chiu said. “This is a way to change how visitors see her work, a way to reach another audience for us.”

The exhibition at the Smithsonian’s museum of modern and contemporary art commemorates the 10th anniversary of the artist’s gift of “Wish Tree for Washington, D.C.,” a permanent part of its sculpture garden. The exhibit also includes “My Mommy Is Beautiful,” an interactive work inviting visitors to share their memories or thoughts about their mothers. Some 30,000 individuals have contributed to the piece, Chiu said. “Sky TV for Washington” and a Sept. 17 concert round out the four parts.

Sunday’s concert will be on the outdoor plaza starting at 7 p.m. Musicians Kim Gordon, Lizzi Bougatsos and Moor Mother will perform selections of Ono’s work and their own, while Ono’s avant-garde films will be screened throughout the evening.