NEW YORK, NY.- The stage manager’s office on the second floor of the Gerald Schoenfeld Theater in Times Square is about the size of half a bathroom and has the charm of a utility closet. It’s crowded and overlit, thanks to a high-wattage vanity mirror situated near a 1970s minisink.

Ingrid Michaelson surveyed the room where we were to begin our interview, and sighed.

“It’s not glamorous at all — but it is,” she said. “There’s just a small, lucky group that gets to see these little rooms.”

With the opening of “The Notebook” on Thursday, Michaelson made the turn from a successful midlist singer-songwriter to Broadway composer. Though other pop writers have made the same foray into musical theater — including Dolly Parton, Cyndi Lauper and Michaelson’s friend Sara Bareilles — Michaelson was an unlikely choice, because “The Notebook” is a huge franchise and she isn’t a hitmaker. “Quirky” is a word that turns up in articles about her, and quirky is rarely a mass-market trait.

Nicholas Sparks’ 1996 romance novel was a publishing phenomenon that has sold 14 million copies worldwide. In 2004, it was adapted into a film starring Ryan Gosling and Rachel McAdams, and its feverishly passionate dialogue (“It wasn’t over. It still isn’t over!” Gosling shouts in the middle of a rainstorm) made it as beloved by fans as it was scorned by critics. Wielding a double-barreled shotgun in his review for The New York Times, critic Stephen Holden dismissed Sparks’ book as “treacly” and called the film “a high-toned cinematic greeting card.”

“I remember watching the movie with my friend. We rented it from Blockbuster,” Michaelson, 44, recalled. “I cried and cried and cried at the end.”

She was dressed casually, in a gray knit cap, baggy flannel shirt and torn jeans. In conversation, she gravitated toward self-deprecation and the spilling-over candor of a lifelong New Yorker.

She was droll and funny but cried several times during our interview. At one point, on the topic of losing our parents, we both cried at the same time.

“The Notebook” begins in an old-age home, where Allie, who has Alzheimer’s disease, doesn’t recognize her husband, Noah. He reads to her from a notebook, which tells the story of how they met and fell in love in their late teens, only to be separated by a conniving parent. They meet again 10 years later, when Allie is engaged to someone else. Will her marital pledge hold firm in the face of true love? We know the answer, but the reward of their reunion is offset by the pain of seeing them both in distress.

THIS IS A PERSONAL SHOW for Michaelson, partly because she wove so much of her parents into the songs she wrote. Also, she had dreamed of working on Broadway since the age of 9 but went off course.

In the fourth grade, Michaelson, who grew up on Staten Island, New York, began acting in a free, city-run program.

“It brought me out of my shell in a way I didn’t think was possible. I was Velcro-ed to my mother, and acting helped me feel like I could do things on my own,” she said.

Her mother, Elizabeth Egbert, was a visual artist who ran the Staten Island Museum, and her father, Carl Michaelson, was a songwriter with a day job at Carl Fischer Music in Manhattan. Extravagances like Broadway shows weren’t in their budget, so Michaelson grew up on summer stock productions. She was accepted to New York University’s Tisch School of the Arts, but she said she didn’t want to saddle her parents with enormous tuition so instead studied theater at Binghamton University, a public school in New York.

She graduated in 2001 and returned to New York City “ready to hit the town and audition,” she said. But after the attack on the twin towers on 9/11 (her father walked more than 2 miles through the carnage to get home), acting began to feel frivolous to Michaelson. “I hate to say 9/11 caused me to start writing my own music, but it did.”

Over the years, she fashioned a thriving niche outside the mainstream music industry, thanks to her ingenuity. She self-released her first album in 2005 and later licensed songs to network TV shows (“Keep Breathing” was featured in a “Grey’s Anatomy” episode) and Madison Avenue (“The Way I Am” soundtracked an Old Navy ad.) Her highest-charting single, “The Way I Am,” peaked at No. 37 on Billboard’s Hot 100 chart.

Michaelson’s career apex came in 2014, she said, with her platinum-selling single “Girls Chase Boys.” That same year, Taylor Swift attended a Michaelson concert and called the show “magical” in social media post. But then things started to fall apart.

Her mother died of sepsis in August 2014 while recovering from surgery to treat bone marrow cancer. Michaelson separated from her husband, songwriter Greg Laswell, who released a tart album largely about her, pointedly called “Everyone Thinks I Dodged a Bullet.” Her father, who had Parkinson’s disease, died in September 2017.

The rise of streaming made musicians more reliant on touring, but Michaelson had tired of going on the road. She sold the rights to her master recordings and songs, except for a few written about her mother.

“The music world felt unsafe to me,” she said.

She fantasized about writing a musical, and texted Bareilles, who had been hired to write the music and lyrics for “Waitress,” which debuted on Broadway in 2016. “You can do it,” Bareilles texted back.

Michaelson was also encouraged by actor Will Chase, whom she’d begun dating. Chase was in the Broadway show “Something Rotten!,” and during an after-show party in January 2017, he turned to Broadway producer Kevin McCollum and said, “Ingrid wants to write a musical.”

A few days later, Michaelson met McCollum at his office in Manhattan, where he mentioned “The Notebook.”

“You know how cats can stand on a couch, do a flip and land in the same place?” McCollum asked in a phone interview. “Her whole body opened up and metaphorically did a full-on flip.”

Michaelson was overcome by the chance, and said she slipped away to the bathroom to cry. McCollum suggested she write a few prospective songs and get back to him. He figured it would take a few months, but two hours later, she texted him a voice memo of a new song, “I Know,” which is in the show.

Given the popularity of “The Notebook,” it might have made sense for McCollum and his fellow lead producer Kurt Deutsch to hire a Top 40 hitmaker. But McCollum has a track record of working with young composers, including Jonathan Larson (“Rent”) and Lin-Manuel Miranda (“In the Heights”).

Michaelson, unwilling to miss out on the gig, began to send McCollum “song after song after song,” she said. “Eventually he said, ‘I think you’re hired.’”

“Ingrid understands the human heart,” McCollum enthused. “I’m not afraid of my vulnerability, and neither is she.”

MICHAELSON BEGAN WORKING with book writer Bekah Brunstetter, who had written for TV (most notably on “This Is Us”) and theater (“The Oregon Trail”), though “The Notebook” is her first Broadway musical. Michael Greif, a four-time Tony nominee, joined as director and later enlisted Schele Williams to codirect. Since the show depicts its two central characters at different ages, they decided to cast a mix of white and Black actors to play the three Noahs and three Allies.

“Michael said, ‘This is something that needs to be done with great care. Would you join me?’” recalled Williams, who is also directing the Broadway revival of “The Wiz” this spring.

Younger and Middle Allie are played by Black actresses, while Older Allie is white. Younger and Middle Noah are played by white actors, while Older Noah is Black. The casting can cause confusion. Friends asked Williams if there was a metaphorical reason Allie “becomes white” when she’s older.

Using white and Black actors in the same role adds to the “expansiveness” of the story, Williams, who is Black, said.

“There have been few times, in epic stories, in which I’m allowed to see myself in a mirror,” Williams said. “If we can say to everyone, ‘This story is also your story,’ that’s an inclusiveness that theater can provide.”

Casting across race necessitated a few story changes. Most notably, Brunstetter moved the setting from the 1930s and ’40s to the ’60s and ’70s, an era when an interracial relationship “could take place and could be probable,” Williams said.

Early in our conversation, Williams mentioned that her mother has Alzheimer’s, and choked up as she talked about caring for her. I’ve lost two close family members to dementia, and I told her that the show is far more frank about the horrors (and occasional comedy) of Alzheimer’s than the movie was.

“It was incredibly important to give dignity and honesty to the subject,” Williams said.

In October 2022, Chris Jones of The Chicago Tribune reviewed “The Notebook” when it played at the Chicago Shakespeare Theater, and raved that Michaelson had written “an absolutely gorgeous suite of songs.” But she knows that, given all the changes made in staging the story, fans of the book and movie might feel betrayed.

“There are people who are unhappy that it’s not the movie,” Michaelson acknowledged. “Some people will come just to hate the show, because it’s another movie-to-musical adaptation. Others will come in expecting to see Ryan Gosling and Rachel McAdams look-alikes onstage. Whoops!‘

“It’s not a big, bombastic musical,” Michaelson said. “Hiring me sent the boat in a different direction — a quieter, more introspective direction.”

In writing songs for Allie and Noah, Michaelson incorporated thoughts she’d had about her mother’s death, as well as comments made by her widowed father.

“I don’t want to talk about my parents the whole time, but there’s a lot of them wrapped up in these songs.”

As a result, she relives their deaths every time she sees the show.

“I really didn’t have any breakdown moments since my mother died,” she said. “It wasn’t until a month ago, in rehearsal, that I completely lost it — like, a loud, guttural, other humans can’t see this crying. You’ve seen me cry eight times already today, so that might not seem convincing.”

As opening night neared, Michaelson, no stranger to creative neuroses, had developed what she said her therapist called “pre-post-mortem anxiety.” Other than a record that she will release this summer, full of what she called “quiet, old-timey music,” she doesn’t know what’s next.

“Being a woman of my age, without children or parents, I am untethered on both sides. I feel like I’m just a tire rolling down the highway sometimes.”

Fulfilling a dream from 35 years ago has been great, she said, but it has also introduced new worries.

“I don’t want to be pigeonholed as the weepy, romantic writer,” Michaelson said, and then laughed. “Even though that’s probably what I’m best at.”

This article originally appeared in The New York Times.