The toilets wouldn’t stop flushing. The playwright David Lindsay-Abaire was trying to talk about his collaboration with the composer Jeanine Tesori and the director Jessica Stone on their musical, “Kimberly Akimbo,” and in the background, the janitorial staff members of the Booth Theater were cleaning the bathrooms.“I said to Jeanine,” he said, trying to keep a straight face as another toilet flushed, “I wish we could write a musical the way that I write a play, where there’s not a team of other people involved.”Another flush.Tesori stood up, muttering, “I have to close that door myself.” Which prompted Stone to bend over in laughter.“Thank you,” Stone said, as Tesori returned to her seat in the basement lounge of the Broadway theater.“It is on theme,” Lindsay-Abaire said. “Nothing better.”“Isn’t that enough?” Tesori responded. “Doesn’t that say everything?”For the creative team behind “Kimberly Akimbo,” the chaotic energy of this morning fit the musical itself, whose concept seems — on the page, at least — too off-kilter for a shiny Broadway marquee.Victoria Clark, center, as Kimberly with Alli Mauzey, foreground left, and Steven Boyer, foreground right, who play her parents.Sara Krulwich/The New York TimesA musical dramedy set in New Jersey, “Kimberly Akimbo” tells the story of a teenager named Kimberly (played by Victoria Clark) who has a disease akin to progeria, which causes her to age at a hyperspeed. At 16, she looks 72.It’s far from a tragedy, though, thanks in part to the quirky characters: Kimberly’s pregnant mother is a hypochondriac; her best friend, Seth, loves anagrams and plays the tuba; and her aunt is trying to persuade her to commit some white-collar crimes. Through it all, even though people with her condition have an average life expectancy of 16 years, Kimberly learns to be young and unafraid after years of taking on adult responsibilities.“I love stories that weave together pain, and hilarity and absurdity. And that, to me, is David and Jeanine, and their work and their sensibility,” said Stone, 52, who has been attached to the musical since 2019. “It’s exhilarating.”When the show premiered Off Broadway last winter at Atlantic Theater Company, Jesse Green, the chief theater critic for The New York Times, called it a “funny and moving new musical.” Led by the producer David Stone (no relation to the director), the show sold out its run, and a Broadway transfer was quickly announced. (As the producer of musicals like “Next to Normal” and “If/Then,” Stone is no stranger to an out-of-the-box concept.) Now “Kimberly Akimbo” is in previews, and scheduled to open on Nov. 10.Tesori, 60, and Lindsay-Abaire, 52, first worked together on “Shrek the Musical” in 2008, and for the past seven years, transforming Lindsay-Abaire’s 2001 play “Kimberly Akimbo” into a musical was their passion project. The focus and intimacy of that partnership, he said, made the musical “the easiest thing I’ve ever written.”He compares writing a musical to working on a puzzle. (He loves puzzles and word games; the show’s title is an anagram.) “It is like dumping a bunch of puzzle pieces onto the table,” he said. “It’s hard when you say, ‘Hey, 20 people, come on in and let’s do this puzzle together.’ But if it’s just the two of you — ‘I have this corner’; ‘I’m working on the edges; let’s get to the middle’ — then it comes into focus. And seldom does that happen with a musical.”Stone, Tesori and Lindsay-Abaire gathered to discuss their process on the first day of previews. These are edited excerpts from the discussion.Clark and Justin Cooley, who are reprising their roles on Broadway. “The two of them give each other really beautiful gifts,” the show’s director said of the actors.Sara Krulwich/The New York TimesDavid, what were the instincts that led you to write “Kimberly Akimbo” 20 years ago?DAVID LINDSAY-ABAIRE I was writing what I hoped would be a great part for an actress that I loved and adored: Marylouise Burke [who starred in the play Off Broadway in 2001]. I wrote a part for her because she and now Vicki [Victoria Clark] have such an amazing young spirit about them, even though they’re actresses of a certain age. And so I wanted to write an amazing part for a great actor. But I also wanted to explore mortality and what it means to truly live in the moment. What I probably didn’t know at the time was that I was also writing about my family in many ways, and things that I was afraid of and angry about.How do you mean?LINDSAY-ABAIRE Uh oh …JEANINE TESORI I don’t know if you can open that door.LINDSAY-ABAIRE Look, I love my family very much. And they messed me up just enough for this play to be what it is. [Tesori pats Lindsay-Abaire’s arm, remarking, “Wow.”] I don’t feel messed up by them. But I feel messed up just enough to be the writer and be the person that I am.TESORI That’s what makes you a storyteller. Healthy enough to write, damaged enough to want to write.The play didn’t have monologues for Kimberly, but it did have monologues for her parents. Was creating the musical a way to create more interiority for her?LINDSAY-ABAIRE During “Shrek,” I said to Jeanine, “I would love to write a musical the way that I write a play, where it would just be us figuring it out for as long as we needed to figure it out.” And then Jeanine said, “Well, how about one of your plays? I think ‘Kimberly Akimbo’ could be a musical. It has a really deep, complicated inner life. Those characters want to sing to me, their emotions are deep. And I like how funny it is.”By making it a musical, we had a way into the characters that the play did not have. We could crack open Kimberly’s heart, and let her express all of those feelings and emotions and fears and desires and longings, that are only subtext in the play.TESORI I feel it in my body when something sings, I can’t put it into words. And these characters, they reminded me of people I grew up with, they reminded me of people in my family — and not always people who are center stage, especially in a musical.Jessica, how did you direct Victoria Clark, who is 63, and Justin Cooley, who plays her boyfriend, Seth, who’s now 19? They come across as being the same age.STONE: It actually is thrilling because you have two people on opposite ends of the spectrum. The skill that Vicki brings to the process of exploration can’t be created in Justin. I watch him being elevated by the discipline and skill, and her surgical approach to figuring out Kim and mapping out Kim’s world and behavior. He starts to sort of mimic that work ethic and he starts to explore and basically copy that approach.His complete honesty, tabula rasa, complete truthful, youthful, wide-eyed innocence and sweetness — it’s really hard to create that once you’ve lived, you know, 35 more years. So the fact that she’s in his orbit, this beautiful, innocent, youthful presence also washes over her. So the two of them give each other really beautiful gifts.Speaking of teenagers, there’s a duality to the show. It’s about youthfulness, but it’s also about mortality. As experienced artists, how do you keep that youthful tone intact?TESORI It’s part of being of a certain age, and what we have all experienced at this age. I’m older than these two. We share the same sensibility of humor. But there’s also this sense, like, we’ve been through some [expletive]. And our friends have been through some [expletive], and we’ve lost people. And if you’re lucky, you’re able to bring both of those things to an audience so they can recognize it. Because I think sometimes because musicals have artifice, they can seem artificial. And they’re not. They are the greatest art form.STONE We’re all parents. And we all have been close observers to adolescents. That adds a little bit to the glaze of authenticity, and a little understanding of the behavior, needs and pitfalls.LINDSAY-ABAIRE The first time in, I was really accessing my teenage years and stuff about my parents and my family, but really homing in on the Seth character who is very close to me in very many ways. I’m now the father of teenage boys, and I just had access to the parents in a way that I didn’t have when I wrote it. I understand much more acutely the fear of losing a child. The whole dynamics between parents and teenagers that I was sort of making up 20 years ago, now I know it deeply and personally. And I also got the chance to put all of my high school friends up onstage. Those four kids in the show choir were not in the play.“If you can have a gaggle of teenagers skipping out of the show, and then this grumpy old man with tears in his eyes — that’s victory,” said Lindsay-Abaire, right.Victor Llorente for The New York TimesDo you imagine this as the kind of show that parents can take their teens to?STONE My kids, 13 and 15, were here, and they loved it. Because I’m so invested in the parent side of the story, and in the mortality side of the story, and in the how-do-you-choose-to-live-your-remaining-days-on-this-planet side of the story, I forget about the delight, the tremendous luxury of hope and time, that teens have. And that enables so much in terms of imagination and promise. [My sons] think it’s hilarious. They love Deborah [Kimberly’s aunt, played by Bonnie Milligan], because they love a rule breaker. They also thought it was really moving. They were really intrigued by the relationship between Kim and Seth, not because it’s a traditional love story. But they really responded to that deep friendship.LINDSAY-ABAIRE Nothing has made me happier than seeing gaggles of teenagers really love the show. But at the same time, at the end of the Atlantic run, a grumpy old man was walking up the aisle and he looked at me and I thought he’s going to criticize the piece. And he said, “I just want you to know that I’m going to go out and live life more fully tomorrow.” My eyes welled up and then he was gone into the night. If you can have a gaggle of teenagers skipping out of the show, and then this grumpy old man with tears in his eyes — that’s victory.In the musical, Kimberly’s aunt sings an upbeat number about how to commit mail fraud. Jeanine, how did you write a catchy song about white collar crime?TESORI [laughs] It’s exposition, which is generally not great for a song. But then I thought, “Oh, if we make it really sort of furtive, and it’s got a little bit of a muted guitar thing, and it’s sort of like Peggy Lee, but maybe on a very, very off day …” It’s having it be fun, so that she can convince the teens to be part of it.LINDSAY-ABAIRE It’s a teaching song. We were talking about “The Rain in Spain” [from “My Fair Lady”], but it’s about check washing. It’s just messed up enough. More