On a small stage, three actors practiced a sword fight — slowly, then faster. Behind them board operators ran a sound check and a wardrobe assistant shook out costumes.

“This is the part of theater you never get to see,” Rebecca Martínez said.

Martínez was speaking on Saturday in the southeast corner of Bryant Park. Behind her, the cast and crew of the Public Theater’s bilingual musical version of “The Comedy of Errors,” performed in Spanish and English, accomplished their preshow rituals. Martínez, who adapted the production with Julián Mesri, is also the show’s director and choreographer. Typically, routines like these are performed backstage, out of sight. But at Bryant Park, amid the birders, the tourists and the library patrons, a backstage was not available.

For over 60 years, the Public Theater has offered summer Shakespeare in one place: Central Park’s Delacorte Theater. This year, the Delacorte is closed for renovations (it plans to reopen next summer, with “Twelfth Night”), so the Public has taken this free show to the streets, parks and plazas of the city’s five boroughs.

This “Comedy of Errors” was seen last year, as a production of the Public’s Mobile Unit, which brings high-energy, low-tech versions of Shakespeare to venues like libraries, correctional facilities and community centers. The Unit travels light, with a rug in place of a set, which allows a simple set up and strike.

“Like, boom! Rug! Let’s go!” Martínez said.

The 90-minute show now has more furniture and two trucks to convey it. As a substitute for Shakespeare in the Park, it has been enhanced with more actors, more musicians, lighting for evening performances and a raised stage. What used to take minutes to set up can take as much as three hours.

I joined “The Comedy of Errors,” which runs through June 30, on its first Saturday. A little before 10 a.m., the sun was high and the breeze was mellow. Fifteen crew members — twice as many as in a typical Mobile Unit production — were trundling dollies, road boxes and ladders from a library loading dock toward the stage. Later, a freight elevator would give out, but for the moment, the process was frighteningly efficient.

“Every place has a different challenge,” said Luisa Sánchez Colón, the production stage manager. “Or a new discovery.”

Bryant Park had allowed the Public to leave the stage up overnight, so this was an abbreviated version of the set up. (Assembling the stage adds an hour or more.) While the crew, in pale blue shirts, busied themselves screwing in steps and attaching speakers, 10 front of house workers, in green shirts, arranged 250 chairs on three sides of the stage. By 11:30, the canopies above the band, audio equipment and check-in desk had been raised.

Praycious Wilson-Gay, the director of the Mobile Unit, pushed a broom across the stage, sweeping off leaves and pollen. She had begun scouting for locations last August, seeking venues with decent accessibility (on-site bathrooms, adjacency to public transport) and by preference, large Spanish-speaking populations.

It would have been easier, of course, to have staged the play at the Public’s downtown hub. “But the artists really want to invite what is happening on the streets of New York City into the life of the show,” Wilson-Gay explained. “Sitting in a brick-and-mortar theater, you don’t get the same experience.”

Mesri, who is also the show’s composer, agreed. “The city finishes the show,” he said. “You feel the city complement the soundtrack.”

The actors arrived at noon, and changed inside the library. Then they walked outside where an audience had already gathered. Because the show changes based on surroundings and crowd, Martínez sought actors who could meet those challenges.

“We have very intentionally funny actors,” she said, “they get excited about how to deepen the show based on how they are interacting with the audience.”

The show began just after 1 p.m. with a procession around the plaza. There were bubbles, roving audience members, divebombing pigeons, a bus that briefly sent feedback screeching through the wireless mics. The actors absorbed it all.

“The city is part of the tapestry of the show,” Gían Pérez, an actor, said.

Then the show was over. After bowing and posing for selfies, the actors joined the crew in tidying away set pieces and folding canopies. “I love it,” Varín Ayala, an actor, said. “In any other show, I’d go, ‘Ew, I don’t want to strike,’ but it’s a part of the experience.”

After less than an hour, the set had been dismantled, the chairs hung on racks and wheeled inside. After a brief meeting, the cast and crew were released. They would meet the next afternoon for ice cream, then set it up all over again.

“You have to have a certain amount of ruggedness,” Martínez admitted. That allows the company to bring theater to people right where they live, work and sightsee. That day, Martínez had brought her husband to the show and her young daughter, who had marched in the procession.

“The payoff,” she said, “is being able to be in community.”