One recent Saturday morning at Steps on Broadway, a rehearsal studio on the Upper West Side of Manhattan, ballet dancers pirouetted to recordings of classical piano music while an instructor guided them.

Some of the dancers were retired pros practicing at the barre. Others were weekend warriors indulging “Swan Lake” fantasies while getting in some cardio. The writer Alice Robb, wearing a pink leotard and ballet slippers, stood out. Her tendus seemed a little more elegant than everyone else’s, and when she jumped into the air for petit allegro, she soared just a little bit higher.

Afterward, Ms. Robb emerged from a changing room in jeans and a gray knit sweater, carrying a Vanity Fair tote bag. As she cooled off, she observed an advanced ballet class, watching the movements of a girl who looked about 13.

“She’s good,” said Ms. Robb. “Very good. Probably S.A.B.”

Ms. Robb meant the School of American Ballet, the elite school that serves as the official training academy for the New York City Ballet. When Ms. Robb was around the same age as the girl she was watching, she was herself a School of American Ballet student. But she didn’t make it as far as City Ballet, having been dismissed from the school at 12.

“I feel sorry because I know what she’ll go through,” Ms. Robb said. “But I also have this envy, because she still has a chance to be a dancer.”

For all those who emerge from the School of American Ballet to make it into the nation’s pre-eminent company, there are many more whose dreams are shattered. In Ms. Robb’s case, she endured an identity crisis that followed her into adulthood. In her new book, “Don’t Think, Dear: On Loving and Leaving Ballet,” which comes out on Tuesday, she repurposes her anguish into prose while also taking a critical look at ballet culture.

The title is an allusion to an instruction given to ballerinas by George Balanchine, the visionary Russian-born choreographer who co-founded the School of American Ballet and City Ballet and ruled over both institutions until his death in 1983. Ms. Robb, a former staff writer for The New Republic, recounts her days performing as a toy soldier in “The Nutcracker” and enduring the disquiet of watching her body grow in a way that did not conform to the skeletal Balanchine standard.

In offering a feminist interrogation of ballet in the post-#MeToo world, Ms. Robb, 31, scrutinizes the legend of Balanchine, who is revered 40 years after his death, questioning the power dynamic of his relationships with the young dancers in his thrall.

She dissects his marriages to four ballerinas, among them Tanaquil Le Clercq, who began dancing for him in her early teens and married him at 23. A few years later, she was stricken with polio and confined to a wheelchair, and Balanchine eventually divorced her to pursue a new muse, the 23-year-old Suzanne Farrell. When Ms. Farrell refused his advances, marrying a fellow dancer, she and her husband were cast out of the company. (Balanchine and Ms. Farrell later resumed their collaboration, a partnership that lasted years.)

“Our bodies were instruments,” Ms. Robb writes. “And they belonged to other people: to choreographers and partners and directors — to men.”

In researching “Don’t Think, Dear,” she interviewed former S.A.B. students who, like the author, never made it to City Ballet. One of them joined a contemporary dance troupe, another went on to teach a gentler adaptation of the Balanchine method at a Christian university in Texas, and a third found work as an extra in Central Casting.

“How did we reconcile our past, and our residual love for ballet with the feminist consciousness we eventually developed?” she writes.

After the young ballerina finished practicing, she ran into the hall to greet her mother. Ms. Robb couldn’t help staring at the girl a little while longer.

‘Wrestling With Ballet’

“My book is wrestling with ballet,” Ms. Robb said at a nearby coffee shop. “If I hated ballet, I wouldn’t have written a book. It’s because I’m wrestling that I wrote it. I tried suppressing it for lots of my life, but eventually I couldn’t anymore.”

This conflict lies at the heart of Ms. Robb’s book. But she says she didn’t find easy answers while working on it.

If Balanchine abused his position, then why did seemingly all of his dancers express worshipful respect for him decades after his death? If his standards were inhumane, then why was Ms. Robb still drawn to the beauty of his choreography?

“I don’t think it’s easy,” she said. “These women have also never really condemned him, and I can’t impose views on women entitled to their agency and opinions.”

“I’m not arguing we should tear him down,” she continued. “But there’s this singular focus on Balanchine at S.A.B. and City Ballet that goes with a kind of hero worship that I don’t think is healthy. Everyone is in thrall to a dead man. And there aren’t many ballet memoirs about what it’s like having a dream deferred.”

Told of the gist of “Don’t Think, Dear,” a spokeswoman for the school said in a statement: “It would be difficult to comment on Alice’s recounting of her three years as a student in S.A.B.’s children’s division without having read the book. We are always extremely proud of our alumni who go on to impressive pursuits outside of the dance world and wish Alice much success with her new memoir.”

Patricia McBride, a Balanchine ballerina who in 1961 became City Ballet’s youngest principal, reminisced in a phone interview about what it was like dancing for him.

“He was a dream person,” said Ms. McBride, 80. “He was a genius. He made us what we all became. We believed in him completely. If Mr. B. said, ‘Jump off a bridge,’ we would have. But we were taking from him, too, because he was giving us something extraordinary, and we were hungry for it.”

Asked for her opinion of a book that is critical of him, Ms. McBride said: “He didn’t expect his life to become a museum of ballet. Balanchine always knew that things were going to change.”

The daughter of an economics professor and a former nurse, Ms. Robb attended S.A.B. from age 9 through 12, when she was a student at Dalton, a private school on the Upper East Side of Manhattan. After she was dismissed from S.A.B. in 2004, she refused to accept the verdict and applied to other ballet schools.

“I look at the girls in the class and I know I will never look like them and I wonder why I am wasting my time,” she wrote in her diary after a disheartening audition. “When I can fly and turn en pointe — that’s when I love ballet and I remember why I dance. But these moments, they are more and more rare.”

After Boston Ballet School’s summer program turned her away, Ms. Robb quit for good at 15. She graduated from Brearley, an all-girls private school in Manhattan, and went on to study archaeology at Oxford University. Then she took an internship at The New Republic, eventually joining the magazine as a staff writer. She left the publication to write “Why We Dream,” a nonfiction book published in 2018 about the science of dreaming.

By her 20s, the ballet keepsakes that she had cherished as a girl — scraps of paper snow from “The Nutcracker” and a poster of “The Dance Class” by Degas — were relics entombed in her Upper West Side childhood bedroom. Still, she sometimes dreamed that she was auditioning for the Bolshoi and thought, “I’m back.”

“I discover that it’s not too late,” she writes. “The exquisite pain of waking up, of remembering that it was just a dream. That I am not a dancer.”

Amid the reexaminations of powerful men that came with the #MeToo movement, Ms. Robb started confronting how she felt about the rarefied world that she had witnessed as a girl. She was rattled when Peter Martins, the director of City Ballet and Balanchine’s successor, resigned in 2018 after accusations surfaced that he had sexually harassed and abused dancers. (Mr. Martins denied the allegations.) Ms. Robb remembered his hulking figure walking into her classes to watch students while her teachers strained to make good impressions on him.

Driven by journalistic curiosity, Ms. Robb began investigating coverage of Mr. Martins’s 1992 arrest on suspicion of having assaulted his wife, the 28-year-old ballerina Darci Kistler. (Mr. Martins was 45 at the time.) Ms. Kistler dropped the charges, however, and days later she arrived at the company to rehearse with Mr. Martins before dancing that evening. A City Ballet spokesman said at the time: “We see this as a personal matter.”

“That got me interested,” Ms. Robb said. “It was completely public that he’d gone to jail, but it was brushed under the rug. Now it’s shocking to read about when you go through old newspaper clips, but the sense among loyalists at the time was, ‘That’s their business.’”

Ms. Robb also started reading memoirs by Balanchine dancers and old books about City Ballet. The details she came across stoked her interest further.

Bettijane Sills, for example, wrote of Balanchine advising her: “You are like inside a cocoon. Your true personality will only be revealed when all the fat is gone, and you are down to your bones.” Another dancer described meeting Balanchine on the street one freezing day, and when he noticed that she badly needed winter boots, he handed her some cash to buy a pair. To Ms. Robb, though, the takeaway was: Why couldn’t he have just paid her better?

In her reporting, Ms. Robb reconnected with one of her S.A.B. classmates, Meiying Thai, who once had been a pupil so promising that Ms. Robb envied her as a girl. Ms. Thai, who became an artist, told Ms. Robb about how she had struggled to advance to pointe work in her midteens and that she never forgot the desperation she felt trying to regain the favor of her teachers.

“I’ve bonded with lots of former classmates, and we’ve learned to look back critically,” Ms. Thai said in an interview. “This art form will die if we don’t challenge it, so I hope we see more books like this. And I’m saying that as someone who has Balanchine technique in my body forever. But I can hold two things at once. He was also problematic. And we should be able to say that.”

Ms. Thai added that she was worried that purists will dismiss her friend’s book as millennial Balanchine bashing. “It’s already started,” she said. “Someone left a mean comment on Instagram, even though they hadn’t read it yet. But there they were, ready at the bat to defend him, no matter what.”

‘Firebird’

Ever since Ms. Robb finished writing her book, ballet hasn’t been on her mind quite as much. But when the spirit moves her, she still enjoys seeing ballet at Lincoln Center. One recent night, she attended a performance of “Firebird,” which was choreographed by Balanchine and Jerome Robbins and is based on a Russian fairy tale.

Seated in the fourth ring, Ms. Robb grew entranced as a ballerina twirled onto the stage to the Stravinsky score swelling from the orchestra pit. During the festive final scene, in which a prince marries a princess, she pointed to a child carrying a cake and whispered: “That was me.”

As the audience streamed out of Lincoln Center, Ms. Robb walked across the chilly plaza and entered the S.A.B. lobby for the first time in years.

“Standing here still invokes a childhood envy in me,” she said. “Maybe regret. Though that’s not the right word. This invokes a childhood dream that became painful because it didn’t come to be. But it all has less of a hold on me now.”

Two ballet students entered the lobby and waited for an elevator. Fit and slender, they glowed with confidence. The doors opened and they stepped in.