NEW YORK — For months now, Thomas Schumacher's dining room table has been taken over by a master list of every Broadway show that's seeking to reopen or schedule an opening night — from the established "The Lion King" to the new "Diana: A True Musical Story." Since the pandemic-related shutdowns, the Disney Theatrical Group president and his colleagues have been working through various scenarios to get New York theater back on its feet.

But a half-year into an ongoing human tragedy and economic calamity that has drained the cultural lifeblood of the city, neither Schumacher — who is also chairman of the Broadway League trade group — nor anyone else knows for sure when the nation’s premier performing arts district will start up again. The earliest estimates for some of New York’s concert halls and theaters to resume are spring 2021; a few new productions, such as “The Music Man” with Hugh Jackman and “Plaza Suite” with Matthew Broderick and Sarah Jessica Parker, have announced early spring beginnings on Broadway. Even so, those involved in the planning say privately that it could be autumn 2021 before venues reopen.

Repeatedly, as science and government grapple with understanding covid-19’s patterns and devastating impacts, arts leaders here — as elsewhere — have had to build and rebuild safety plans for both arts workers and audiences. At the city’s pace-setting institutions — the 41 theaters of Broadway, the campus of Lincoln Center, the dance and music and other performance spaces of downtown and the outer boroughs — dates for reopening have been set and then pushed back, as the logistical questions evolve and multiply.

The task has proved far more daunting than anyone could have imagined, amounting to a struggle of wrenchingly complex proportions with no reliable end in sight. And at this point, though, Broadway — the ultimate land of make-believe — is holding on to a hope that early 2021 is still feasible. “I am believing that this spring we will be back because we have to commit to it,” Schumacher said. “We have to come back. And we have to gird our loins.”

Amid the upheaval of the coronavirus pandemic and the 2020 school year, The Post's Peter Marks and Everdeen Mason recommend school-based musicals and books. (The Washington Post)

Still, he and his colleagues are wrestling with monumental challenges: How do 10 or 20 or possibly even 30 productions — all essentially starting from zero in ticket sales — manage to reanimate Broadway all at once? How is the industry’s limited rehearsal space assigned? How staggered do the reopenings have to be? Should shows that were struggling before be gently encouraged to throw in the towel?

Broadway alone accounts for more tickets sold each year than for all of the metropolitan area's professional sports teams, and the industry pumps on the order of $13 billion annually into the city economy. It seems fair to say, then, that until the return to health of the performing arts, the city cannot really be said to be back.

The problems for theaters and concert halls — ventilation systems in need of updating, cramped quarters for artists and other workers in backstage areas, a lack of specific federal guidance about what safety measures are required, and a host of other issues — are bedeviling the path back for the purveyors of some of the world’s premier venues and attractions. Some of Broadway’s theaters, such as the Belasco and Lyceum, date back to just after the turn of the 20th century, with narrow passageways and dressing rooms, sometimes shared, that are more like closets. An actor’s quick costume change in a tiny nook backstage can require two or even three assistants, all breathing in the same few cubic feet of oxygen.

Such is the degree of difficulty that while the city’s flagship art museums are already reopening, with state- and city-approved controls on capacity and mandates for masks, theaters have no firm restart date.

The timetable hinges on advances in detection and prevention of the novel coronavirus, via development of rapid testing and vaccines. These are crucial in the commercial domain of Broadway, where social distancing is an untenable remedy for multimillion-dollar productions that require their 1,000- to 2,000-seat spaces to be filled to near-capacity to be profitable. Museum directors like Adam Weinberg of the Whitney Museum of American Art say they have been able to demonstrate that their air-filtration systems and crowd-control procedures are adequate. Performance venues have not.

As Scott Rudin, producer of now-dormant Broadway hits such as “The Book of Mormon” and “To Kill a Mockingbird,” explains, the other variables that must be taken into account are mind-boggling. “How many shows come back and at what level of attendance?” he said in a Zoom interview. “What will labor do? What will [theater] owners do? What does working from home mean for the nightlife of New York? What happens to hotels, restaurants, tourism? How many people leave the city and don’t come back?”

Tallying the financial losses to a bedrock sector of the New York economy is itself a gargantuan task: In the six months since the historic shutdown began — a closure without parallel in American life — the jobs of thousands of performers, directors, designers, stagehands, ushers, box-office workers, administrators, publicists and more have been cast into limbo. The aid doled out by the federal Paycheck Protection Plan and unemployment benefits helped arts staffers hold on, but now, stories abound of performers and other creative-economy workers leaving the city.

The financial losses are staggering, and mounting: Consider that for the period in 2019 of the second week in March to Sept. 1 — the length of the shutdown so far — Broadway alone took in $853 million in ticket sales.

“In my neighborhood, I’m watching three people move away a day,” said Warren Adams, a choreographer who, with actor T. Oliver Reid, created the Black Theatre Coalition to help bring more people of color into the industry. Reid added: “I have friends, couples, who are both in the business — people with Tony nominations — their work stopped and they have no money coming in. How are we looking at this as a culture, as an industry?”

Marcy Richardson is hanging on, but only barely, and she’s both angry and illustrative of how the pandemic has upended artists’ lives. A classically trained opera singer who lives in Brooklyn, she honed a second specialty as an acrobat and has worked steadily for years in variety shows and high-end burlesque, with avant-garde troupes such as Bushwick’s Company XIV and event producers including Susanne Bartsch. Now, as the $75,000 she made last year as a singing aerialist goes to zero, Richardson, 40, doesn’t understand why government aid has not been solidified to help sustain backbone-of-the-city steady earners like herself.

“We are small, locally owned businesses that are trying to make art a business,” she said. “I’ve never felt less valued and so disrespected as an artist. I want to know, ‘Do you not care if we disappear into thin air?’ ”

At this point, federal aid for the arts sector exists on paper only: Sens. Amy Klobuchar (D-Minn.) and John Cornyn (R-Tex.) introduced the “Save Our Stages” bill this summer, seeking $10 billion in relief aid for live venues. But its chances in the short term are not good.

“It felt more realistic in June than in August of an election year,” said Narric Rome, vice president of government affairs and arts education for Americans for the Arts, an advocacy group. “There are definitely not too many members of Congress who want to talk about that right now.”

Richardson’s plea resonates with another issue outlined by Henry Timms, president of Lincoln Center for the Performing Arts, which runs 30 indoor and outdoor facilities on a 16-acre campus housing the Metropolitan Opera, New York City Ballet, Lincoln Center Theater and nine other organizations: how this turbulent time affects not only the bottom line, but also the psychology of a city that prides itself on its cosmopolitanism.

“We frame this conversation in terms of economic recovery,” Timms said in an interview. “But actually the biggest question is about social recovery. The arts in general have a critical place in terms of recovering from the pandemic, and the really interesting challenge for the arts — when we are seeing some of the worst of ourselves — is that the arts represents the best of ourselves. The job of the arts is to be part of that human recovery.”

Culture is one of New York's most invigorating lures: In 2019, leisure travel, of which the arts is a huge component, accounted for 53 million visitors to the city. Privately, Broadway insiders report they have had to explain to New York state officials, eager for Times Square to come alive again, that even with new protocols in place, revival is a months-long endeavor, requiring facilities upgrades, marketing campaigns and a coordinated strategy for unveiling new shows and reintroducing long-running hits. A new TV spot by NYC & Company, the city's official convention and visitors bureau, hints at how far off normalcy remains: The 30-second commercial, telecast during the crowdless 2020 U.S. Tennis Open in Queens, stresses the city's people and its neighborhoods. "Big emotions. Intimate moments. Grit," reads the spot's messaging, intermingled with shots of everyday New Yorkers.

No words appear about more traditional tourist attractions — because there are no tourists to appeal to, foreign or domestic, and few for the foreseeable future.

The emphasis, said Chris Heywood, NYC & Company’s executive vice president of global communications, is to motivate local residents to explore the city.

“We really need New Yorkers to help us rebuild the vibrancy of the city,” he said.

The needs, though, of musicals and symphonies and ballet companies are profoundly intertwined with other amenities, like restaurants and hotels, being back in full swing, too. As one arts leader, speaking on the condition of anonymity because of the sensitivity of the issue, observed: “The city can’t come back without Broadway. But Broadway can’t come back without the city being somewhat what it was before.”

The practical challenges of recovery are so vast that Broadway has set up, through its trade group, the Broadway League, 42 task forces to address the crisis. Some 350 of its 800-plus members are involved. “There are 20 labor task forces, one for each union,” said Charlotte St. Martin, the league’s president. Ten others are tackling marketing issues; five are set up to interact with the city, state and federal agencies. Two Washington lobbyists, one with ties to Democrats, the other to Republicans, have been hired to seek stimulus funding for arts venues and artists in proposed legislation; epidemiologists and industrial hygienists are advising on safety and air filtration. The issues are as diverse as how to handle intermissions, when longer bathroom breaks may be required, to what kind of financial aid or tax credits the government might devise.

“We have developed protocols for over 200 actions,” St. Martin added, “everything down to the minutest protocols, for example, for how to protect wig dressers. And we are talking to the city. They may very well close down some of the side streets [of Times Square] to give us easier theater ingress and egress.”

Among the most pressing concerns is the health of the people who will be in the theaters and halls every day.

“From our perspective, the top of the list is safety,” said Kate Shindle, president of Actors’ Equity Association, which represents 51,000 actors and stage managers. The union has been evaluating the protocols being put in place by companies across the country, recently okaying a plan by the producers of “Diana: A True Musical Story,” about Princess Diana, to film a performance on a Broadway stage without an audience. It will appear on Netflix before a Broadway run currently set for next spring.

Still, the lack of basic guidance from the federal government has contributed to the slow progress, the union says.

“This is a frustrating thing for live performance to be open, because there is not a national strategy on testing,” said Mary McColl, executive director of Actors’ Equity.

Another problem is a fragmentation of responsibilities: Union members on Broadway are employed by producers, not theater owners, and it is the latter who would have to pay for structural upgrades such as ventilation. According to Schumacher, of Disney Theatrical Group, before his company moved its now shuttered musical "Frozen" to Broadway, he split the $1.5 million expense of upgrading the entire heating, ventilation and air conditioning system of the St. James Theatre with its owner, Jujamcyn Theaters. Other theaters will need to improve their air-scrubbing capabilities, too, to meet contemporary mandates. The costs could run to $500,000 per venue.

The “legacy shows” — “The Lion King,” “Hamilton,” “Wicked” — are expected to get back up to speed. But an anxiety, industry insiders say, is that other shows will limp along and then fold, contributing to an image of diminished strength. As the producer who spoke on the condition of anonymity put it: “The damage that those shows can do to us is great because they’re going to waste a lot of people’s attention just to sell no tickets.”

And then, of course, lowering ticket prices to lure audiences back may also mean negotiating temporary salary reductions for the various unions. “Is there going to be a robust dialogue about pay rates? Of course there is,” Schumacher said. “But people want to come back to work and be safe.” However, Actors’ Equity’s Shindle said that pay cuts “have not been discussed with us.”

Off-Broadway and off-off-Broadway artists and companies are engaged in their own struggle to come back. Risa Shoup, interim executive director of the Alliance of Resident Theaters/N.Y., a support arm of off- and off-off Broadway, says shows produced outdoors are the first signs that companies are poised to weather the crisis.

Last month, in a community garden in Bushwick, a troupe guided by Rachel Chavkin’s organization, the Team, produced Ellpetha Tsivicos and Camilo Quiroz-Vazquez’s “Quince,” an immersive playlet with music about a quinceañera celebration. Audience members and the actors wore masks, and the crew was trained by a certified covid-19 infection control agent. As 40 or so spectators sat in socially distanced chairs, an emcee on a PA system kept the performers in line.

“Cindy, pull your mask up over your nose!” she demanded of one of the actors onstage.

Other performative seedlings are starting to take root. At Lincoln Center, Timms said, plans are being worked out for a 400-seat socially distanced outdoor space for ballet and other arts, and the New York Philharmonic sponsors a truck circulating all five boroughs and presenting pop-up concerts.

“The challenge is a new way for us to meet our missions,” he said, adding that the campus has been repurposed for other community uses: It served this summer as one of the distribution sites for the Food Bank for New York and is being offered as a polling place this fall.

The old missions remain vital as well. Jeffrey Seller, lead producer of “Hamilton,” said that when things do finally get back to something recognizably functional, he’ll have a backlog of four new musicals waiting to be unveiled, in four successive seasons.

“There will be an explosion of creativity when we return,” he said. “I believe in my heart and in my soul that when we feel confident, we’re all going to be back together. We need it. We yearn for it.”