Meet the real-life Rockette who inspired a glittering new novel

Fiona Davis writes gripping historical dramas set in New York City’s most glittering landmarks, from the Frick Collection to the Chelsea Hotel.

But in 2021, 81-year-old Sandra Lachenauer contacted Davis through her website suggesting another location: Radio City Music Hall.

“She said, ‘You know, I’m a former Rockette and if you want to know all about Radio City, you should call me,’ ” Davis tells The Post.

“So I did, and she just had such an incredible memory for everything that she’d done and the details of what it was like to dance there that I thought, ‘Okay: I’m gonna have to do this.’ ”

The result is “The Spectacular” (Dutton, out now).

The novel follows Marian, a plucky young dancer in the 1950s, who defies her family’s expectations when she runs away from home to join the Rockettes — right as a mysterious bomber is terrorizing the city, leaving explosives in some of the Big Apple’s most iconic landmarks.

Davis interviewed about a dozen Rockettes in the course of her research, but Lachenauer proved to be an invaluable resource, plying her with old programs and photos from her time there, as well as reading a manuscript and providing notes for Davis to make her tale as authentic as possible.

“I was really intimidated because I don’t have a dance background,” Davis explains.

“[But Lachenauer] mentioned that she had some archival material that she could send me, so I had things like the daily schedule, a floor plan, a map of what it was like.”

Lachenauer even helped her with a chase scene set backstage. “I said to her, ‘Where would someone hide?’ And she came up with that [part of the book].”

Lachenauer — now 83 and based in Monmouth Beach, NJ — danced with The Rockettes from February 1959 till July 1963.

Like Marian in “The Spectacular,” Lachenauer joined the troupe when she was 19 and lived in the famed Rehearsal Club, the all-ladies boarding house on 53rd Street for aspiring ingenues.

“Right before I moved in, Carol Burnett moved out,” Lachenauer tells The Post.

“I was 19 and having a great time.”

Lachenauer, who goes by Sandy, grew up in a small town in Illinois and had never heard of the Rockettes before her best friend joined the troupe.

The next year, Lachenauer auditioned too. After she made the cut, the line captain got her a ticket to the next show.

“I was in awe because I had never seen them perform,” Lachenauer recalls.

“I said to her, ‘Oh, I don’t know if I can do that.’ And she looked at me and said, ‘Oh yes you can.’ ”

Lachenauer danced at Radio City for three and a half years. She even met her husband, Bob, in the Hall.

“He came in just a few months after I did and was apprenticing in the electrical department,” she says.

“He was a catch — there weren’t many bachelors in the music hall. So he had quite a bunch of girls after him. But I always say to him, ‘You chased me. I didn’t chase you.’ ”

Lachenauer ended up quitting the Rockettes when she was pregnant with her first of three children.

She eventually opened her own dance studio, teaching ballet in suburban New Jersey.

She says her passion and her happy memories inspired her to reach out to Davis.

“I had read all her books,” Lachenauer says. “I really like her style of writing.”

Even after dancing in one of the most famous theaters in the world, Lachenauer said that helping Davis write her latest tome was a unique thrill.

“Have you ever been so shocked you couldn’t stop looking at something?” she asks.

“That’s how I felt when I looked at my phone and saw that Fiona answered me.

“I am beginning to feel like Gloria Swanson in ‘Sunset Boulevard’ coming down the stairs, saying, ‘Are you ready for my close up, Mr. DeMille?’ ” she says, just as she is about to hang up the phone to go to her seniors tap dance class.

“Either that or Carol Burnett’s version of it.”