If the Broadway musical “Fun Home” has a signature tune, it’s “Ring of Keys.” It’s a sweet ode sung to a butch lesbian by a 10-year-old girl on the brink of discovering her sexuality. For composer Jeanine Tesori and book writer-lyricist Lisa Kron, it’s the first complete song they wrote together. For audiences, it’s a standout moment, and for TV viewers, it’s the song from the show that they’re likely to hear on Tony night.

But when the show’s creators first talked about musicalizing the moment, Kron thought it was a terrible idea.

Nominated for 12 Tony Awards including the top trophy for new musical, “Fun Home” is based on the graphic memoir by “Dykes to Watch Out For” cartoonist Alison Bechdel about growing into her sexuality and coming to terms with her relationship with her father, who killed himself when she was 20. Adapting the densely layered, timeshifting original for the stage — where three different actresses play Alison at different times in the character’s life — proved a challenging process of ongoing refinement that continued even after the musical’s explosive Off Broadway success in 2013.

“Ring of Keys” came early in the musical’s development, but it had its challenges, too. For one thing, playwright Kron (“Well”) shied away from adapting the moment, in which the sight of a UPS delivery woman, described in one of Alison’s lines as “an old-school butch,” awakens a kinship in Small Alison, the youngest version of the show’s protagonist. In the memoir, the incident takes up barely a half-dozen comic panels; on stage, the delivery woman isn’t portrayed by one of the show’s cast members, but seen only through descriptions of her.

“I was concerned with how to write about butchness for what would presumably be an audience that is not completely made up of lesbians,” Kron recalled. “I didn’t know how Alison could talk about that delivery woman without the audience laughing at her. This is is a stock target of ridicule. I didn’t believe we could do it.”

But Tesori (“Violet,” “Caroline, Or Change”) persisted. “It wouldn’t occur to me not to write a song like that,” she said. “This is a song of identification that is a turning moment, when you think you’re an alien and you hear someone else say, ‘Oh, me too.’ It’s a gamechanger for Alison. And that’s just Musical Theater 101.”

From FUN HOME: A Family Tragicomic by Alison Bechdel. Copyright © 2006 by Alison Bechdel. Reprinted by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.


So Kron gave it a shot. “I looked for language that wouldn’t be trigger language,” she said. “I couldn’t say ‘combat boots’ or ‘steel-toed boots.’ I had to comb through and look for words that would both be completely what Alison is seeing, and feel like emotionally where her attention landed, and that would also give the audience a picture of this woman that didn’t have a bunch of stereotypical associations.”

Coming up with phrases including “lace-up boots,” “just-right clothes” and that titular “ring of keys,” Kron handed her ideas off to Tesori, who worked them into a song structure with some lyrical blanks that Kron went back and filled in. (The duo worked  that way through much of the show’s development, they said.)

The result is one of the production’s most memorable moments, not only because of the song itself but also where it falls in the show. Although the song depicts something that happens relatively early in Alison’s life, the story’s remixed chronology means “Ring of Keys” arrives well into the musical’s second half.

“You get it late in the show, so it’s a release to shed all the layers of what’s very complicated and tough about the show, and you just get to be with this girl in a very present-tense way in a moment that is lifechanging to her,” said director Sam Gold (“The Flick,” “Seminar”), the third member the show’s creative triumvirate. “And because you get to experience it already knowing that the future is so complicated, the simplicity of the song is made more powerful.”

“Fun Home” opened on Broadway April 19 to critical raves that matched the glowing reception the show received when it premiered as part of the 2013-14 season at Off Broadway’s Public Theater. But even with downtown success in their back pocket, the creators kept tweaking and rethinking.

Take, for instance, the song “Al for Short.” It got cut after it appeared in the entire Off Broadway run, as well as on the cast recording that came out of it. “I felt like that was the one place in the show where we were treading water,” explained Gold.

The change sparked a flurry of puzzle-solving to come up with new material (the song “Party Dress”) to fill the hole. “Because there’s so much density of story in the book, there has to be density of storytelling here,” Kron said. “So much of the way the songs came together in this show was about all these different ideas and information and thematic material and story events that had to be layered into each moment.”

The relentless, merciless impulse to keep honing was all in the service of getting the delicate interplay of the musical’s throughlines just right. That goes for “Ring of Keys,” too, which, given the fractured timeline of the narrative, could have appeared anywhere in the show, but proved most effective in the latter half.

“Should it be the second song? Should it be the 17th song?” Tesori recalled the creators asking themselves. “It bounced around. But then we found it.”