Will Rawls was waiting in the Lorimer Street subway station one recent Sunday, trying to get to a rehearsal in Chelsea—Rawls is the choreographer for a new opera about Robert Moses, the dictatorial city planner, and Jane Jacobs, the populist city un-planner—when he had a thought. The L train wasn’t coming, and pretty soon, with repairs threatening to suspend service between Brooklyn and Manhattan for more than a year, the train wouldn’t be coming at all. “I was, like, this shit is always broken,” Rawls said, after arriving in Chelsea. “I almost want Robert Moses 2.0 to come back and fix the M.T.A.”

“That’s a very human emotion, to want a Moses-like figure to come in and fix everything,” Joshua Frankel, the opera’s director, said.

“What did Moses do about public transit, anyway?” Rawls asked.

“Starved it of money,” Frankel said, with a shrug.

The opera, “A Marvelous Order,” which will be presented* next month, has two acts—“Robert Moses wouldn’t fit inside a one-act play,” Rawls said—and traces Jacobs’s mid-century fights against Moses’s attempts to build a four-lane road through the middle of Washington Square Park and a ten-lane crosstown expressway along Broome Street. Jacobs thought that Moses was trying to “Los Angelize” New York. Moses thought the only people opposing his plans were “a bunch of mothers.”

“The requisite background reading took some time,” Judd Greenstein, the opera’s composer, said, referring to “The Death and Life of Great American Cities,” Jacobs’s four-hundred-page ode to city life, and “The Power Broker,” Robert Caro’s thirteen-hundred-page biography of Moses. “If you bring the physical book on the subway, people love talking to you,” Frankel said, noting that few riders sided with Moses, save for a couple of Long Island residents wistful for his unrealized bridge from Rye to Oyster Bay.

An urban-planning opera is perhaps no longer strange—thanks, “Hamilton”—but it does present a number of challenges. The source material, for starters, isn’t exactly “The Marriage of Figaro.” “It’s not easy to fit ‘Lower Manhattan Expressway’ into verse,” Tracy K. Smith, the Pulitzer Prize-winning poet, who wrote the libretto, said. (Sample line: “We’ll have to issue new bonds to cover these costs.”) In the rehearsal, Greenstein coaxed a baritone who was playing an employee of the Triborough Bridge and Tunnel Authority to pronounce “you” more like “youse,” and deliberated on where to put the musical rest in the phrase “Interborough Parkway.” Dashon Burton, the opera’s Moses, was struggling to enunciate his character’s decree to “Drive the first stake,” which kept sounding like “Drive the first take.”

“That’s Moses’s mantra,” Greenstein said. “He happened to choose something that’s impossible to say.”

During the rehearsal, Megan Schubert, who plays Jacobs, ran through an aria from a municipal hearing—“Maybe the cars would be happier without the impediment of sidewalks and neighborhood blocks”—but much of the focus was on helping Burton, a bass-baritone, who was wearing hot-pink Converse All-Stars, to make Moses into less of a villain and more of an antihero. “Jane is our Moses figure, Biblically speaking,” Frankel said. “But it’s not very useful to look at them as ‘pure’ Jane Jacobs and ‘evil’ Robert Moses.” Moses razed neighborhoods and displaced families, but he also built Lincoln Center. In one scene, Christopher Herbert, who plays a Moses underling, is tasked with telling his boss that a plan to bulldoze through a cemetery to make way for what would become the Jackie Robinson Parkway was being stalled by families upset that their relatives’ remains would be disinterred. “It’s not quite like going to Darth Vader with bad news,” Greenstein told Herbert.

“You’re nervous,” Frankel said. “But he’s not going to make you start to choke.”

“So it’s more ‘The Devil Wears Prada’?” Herbert said.

“Thank you for choosing a less nerdy example,” Greenstein said, before turning to Burton. “Dashon, any questions?”

“When I sing ‘Why should the dead lie in the way of progress for the living?,’ is it mocking?” Burton said.

“That’s genuine,” Greenstein said. “It’s a love for the people who live in the city now.”

“From an intention point of view, you believe it,” Frankel added, before offering further encouragement. “Everything’s so transient these days. Moses builds for perpetuity.” Burton nodded skeptically, then asked about the motivation behind another one of his lines: “By now, I think the dead have gotten where they’re headed.”

“That’s a joke,” Frankel said. “We need all the jokes we can get.” ♦

*An earlier version misstated the production status of A Marvelous Order.