Last year, after the COVID-19 pandemic shut down Broadway and the West End indefinitely, Andrew Lloyd Webber was desperate to find a way to safely reopen theaters. The composer of some of the world’s most iconic musicals hit on the idea of staging two of his most popular shows, “The Phantom of the Opera” and “Cats,” in South Korea, where strict testing and tracing protocols had helped the country better deal with the global health crisis. Lloyd Webber was hopeful that the productions could demonstrate to officials that with the right measures in place, live events could take place without outbreaks.

“We’ve got to get open again,” Lloyd Webber says. “And I don’t just mean Broadway or London. I mean regional theaters and nightclubs and live music.”

When Sammi Cannold, a theater director and filmmaker, learned from her friend Kristen Blodgette, a music supervisor on Lloyd Webber’s shows, that “Phantom” and “Cats” were about to welcome back theatergoers in South Korea, she thought she had the makings for a documentary. Cannold enlisted her mother, Dori Berinstein (the producer of “The Prom”), to serve as a co-director on the project, while getting permission from Lloyd Webber’s team to embed with the performers. Together, the pair turned Cannold’s hunch into “The Show Must Go On,” a tribute to those who risked it all to get back onstage.

“I felt we had to document it,” says Berinstein. “It was history and it would give hope to all of us in the theater community to not give up.”

Berinstein, who suffers from asthma, stayed behind to advise from New York, while Cannold took her camera to Seoul. There, she quarantined for 12 days in a nondescript hotel along with the cast, and then chronicled the extensive COVID protocols that were put in place during rehearsals and at performances. Mask wearing was strictly enforced for audience members, who also had to undergo temperature checks and be sprayed with a mist of disinfectant.

“Korea had musicals running for much of the pandemic, with theaters operating many times at full capacity,” says Cannold. “And yet there were zero cases of audience-to-audience transmission.”

Lloyd Webber’s gambit didn’t entirely pay off. Theaters are still closed in New York City, and London stages aren’t expected to reopen until later this spring. However, the filmmakers believe that the Korean productions of “Phantom” and “Cats” still provide a template for when the government gives a greenlight for theaters to open their doors.

“It’s not like we’re going to flip a light switch and everything will be the same way it was in March 2020 before things closed down,” says Berinstein.