For those wondering where the title Falsettos comes from, William Finn—like a character from one of his own musicals—delivers an observant and self-effacing explanation. “I thought that Falsettos were voices out of the normal range, and I thought that these characters were characters out of the normal range. That was my attempt at metaphor,” he says with a dry laugh.

Before there was Falsettos, there was In Trousers, the first musical in the trilogy that includes March of the Falsettos (1981) and Falsettoland (1990). Playwright James Lapine came on board as director of March of the Falsettos and Falsettoland (to which he also co-authored the book), but fans may be surprised to learn that In Trousers was technically the duo’s first collaboration, even though Finn himself wrote and directed the first musical.

“James designed the cover of the record of In Trousers,” Finn reveals. “He used to be a graphic designer. I remember that I chose green and yellow for the cover, and he said, ‘Are you out of your mind? We are doing this in purple and lavender.’”

“And so the collaboration began,” adds Lapine.

It was Playwrights Horizons artistic director André Bishop who urged the two writers to work together. “I was desperate for success,” recalls Finn, who called Lapine himself to bring him into the creation of March of the Falsettos. “I didn’t even know that we knew we were writing together,” Lapine says. “I hadn’t ever done a musical.”

While Finn is open about his hunger for success and recognition, Lapine admits that he didn’t feel pressure taking on his first musical. “None of us had careers anyway,” he laughs. “I was just kind of playing. I used to do the staging at night after the actors had left with Michael Starobin, who was the musical director. We rehearsed the show in the place we performed it. I remember it being fun,” he says.

“It was totally fun. You made it fun,” Finn chimes over Lapine. Lapine continues, “It was kind of like child’s play, which is what theatre really is. It was like a puzzle.”

Both artists admit that the material presents challenges in writing and structure. Stephen Bogardus, who created the role of Whizzer in the original productions, recalled that the musicals are full of scene transitions that seem to take a complete left turn dramatically. “It’s a total jump cut, and you have to just go with it,” he recalled.

Finn says he was aware from the start that March of the Falsettos would be especially difficult to stage. “I would say to him, this is impossible to stage, like ‘Four Jews in a Room Bitching,’ and then [James] came up with something,” he recalls. “And I said, ‘Thrill of First Love,’ I don’t know how you’re going to do this,’ and then he had people on wheels. Every day I would come in and think, ‘This guy’s a genius.’ I was writing these things that have proved very difficult to stage, and Lapine figured out how to stage them.”

Audiences who saw the original Off-Broadway and subsequent Broadway production (which united March of the Falsettos and Falsettoland into what we now know as Falsettos), will recall the grid design used on the stage, a direct reference to Lapine’s background.

“Because I was a graphic designer we made a grid on the floor, which is what you did as a graphic designer, you started with a grid. And then it became getting people from here to here on the grid,” he says.

What Lapine and Finn couldn’t foresee with March of the Falsettos at Playwrights Horizons in 1981 was that an abyss waited just beyond the edges of that grid. The AIDS crisis had just begun to dawn.

When the two reunited to write Falsettoland in 1991, the gay community had been ravaged by the disease.

“I dreamt Falsettoland,” Finn recalls. A key scene was solidified from the very start. According to Lapine, “We knew it was going to be about the bar mitzvah, and once we knew it was happening in Whizzer’s hospital room, the show was not very hard to write.”

“During the day we were going to the hospitals, and people were dying. It was a horrible, horrible, horrible time,” Finn remembers. “I was so glad I could respond to it in some way that I hoped would make a tiny difference.

“Because we knew the ending, I constantly felt during the writing of the whole thing that the audience was going to be way ahead of us, and I was shocked that they weren’t,” he continues.

In fact, audiences were living moment to moment with the onstage story because it hit so close to home. “There were people hysterically crying in the theatre, and I found out that many of them had AIDS. You didn’t know unless people looked sick. It was a terrible, terrible time,” Finn says.

In an era where for many HIV is managed as a chronic disease, and new medications provide preventative options, Falsettos stands as a musical history lesson for the younger generation of theatregoers both from the LGBT and straight communities. In the wake of the recent U.S. presidential election, the musical’s return to Broadway couldn’t be more timely.

“I teach musical theatre writing at NYU, which is very gay aware, let’s say, and I don’t think they have a clue what happened during that time,” Finn says. “They are constantly surprised when they respond to my song ‘Mark’s All-Male Thanksgiving,’ which was the last moment I remember feeling great hope. It was the moment we thought we had the world in our hands, and we thought everything would start changing. And the fact that AIDS interrupted this feeling of possibility is just so horrible. It was the ugliest joke in the world. Just when we felt things were changing, AIDS came along. The fact that AIDS revealed people to be gay, who no one knew to be gay, I think that’s the reason gay marriage happened. People were no longer afraid of people who were gay. They were their uncles, their neighbors, their friends.”

For Finn, writing Falsettoland enabled him to put his anger, rage, and hope into his art. The tragedy of Falsettoland and Whizzer’s illness, delivered one of musical theatre’s most emotional musical scenes, “Unlikely Lovers,” in which Marvin, Whizzer, and “the lesbians next door” (Cordelia and Dr. Charlotte) affirm their love and commitment in the face of an uncertain future.

It is a song that musical theatre fans await during Falsettos; a moment that is so awash in emotion it is not unusual to hear and see audience members openly crying.

The Falsettos composer-lyricist lights up when asked about writing the song, and his response is classic Finn: “I remember it exactly. ‘Unlikely Lovers’ is the only song in the show that I wrote without a lyric; it was music first. I knew then, ‘Do Not F**k This Up,’ this is a really good song!”