Allan Corduner (Colonel Pickering) talks to Laura Benanti (Eliza Doolittle) before they go on for the Ascot scene in “My Fair Lady” at the Lincoln Center Theater in New York. (Chris Sorensen for The Washington Post)

Applying makeup at her dressing table as a movement therapist works on her neck and shoulders, Laura Benanti contemplates the mountain she’s about to scale. Two performances as Eliza Doolittle lie ahead of her on this wintry Saturday in the Vivian Beaumont Theater, an afternoon and evening of the exhausting and exhilarating exertions of “My Fair Lady,” the beloved show by Alan Jay Lerner and Frederick Loewe that is sometimes described as the perfect musical.

Could she dance all night? If asked, she no doubt would. That this role finally landed in Benanti’s path — when she’d just about given up hope that it would — made each night of performing “Wouldn’t It Be Loverly?,” and all the rest of it, perhaps even more loverly than she ever dared to hope.


Laura Benanti gets ready for a matinee performance. (Chris Sorensen for The Washington Post)

“I’ve been imagining my whole life how to play her,” the actress, 39, says as she smudges black eye shadow on her cheeks for her first entrance as a grimy Covent Garden flower girl. “The fact that it came back around is an affirmation for me that any door that is meant to open for me, will.”

The door opened in the midst of the run of this hit revival — which opened nearly a year ago as a production of Lincoln Center Theater, directed by Bartlett Sher — after the departure in the fall of its original star, Lauren Ambrose. It’s only the second time in a Tony Award-burnished Broadway career that Benanti, mother of a high-spirited 2-year-old named Ella, has “replaced” in a musical. The first was two decades ago, as Maria von Trapp in a revival of “The Sound of Music,” starring Richard Chamberlain. (The Tony was for her portrayal of Gypsy Rose Lee in “Gypsy,” with Patti LuPone.)


The cast enters a scene during a performance of “My Fair Lady.” (Chris Sorensen for The Washington Post)

Now, along with three other principal actors joining the production — Rosemary Harris as Mrs. Higgins, Danny Burstein as Alfie Doolittle and Christian Dante White as Freddy Eynsford-Hill — Benanti had to adjust to a show whose rhythms were successfully set. And it had to adjust freshly to hers after she joined the production in late October.

“How you holding up?” asks the V.I.P. allowed into her dressing room minutes before the 2 p.m. curtain. Benanti looks up to see her friend Lin Manuel-Miranda, who’s popping in between rehearsals deep in the bowels of Lincoln Center for a benefit performance of “Camelot,” in which he’s playing King Arthur. Phones are pulled out for that sacred ritual: proud-parent-photo-sharing. Miranda once composed a cool rap for a Web series of Benanti’s; now their conversation veers to topics such as poop.

“My son wrote a song called ‘I Just Want to Eat Bread Now,’ ” he says, laughing, as Benanti beams.


Harry Hadden-Paton (Henry Higgins), from left, Rosemary Harris (Mrs. Higgins) and Allan Corduner (Colonel Pickering). (Chris Sorensen for The Washington Post)

And so a full day backstage for a reporter begins, to record an experience both predictable and unexpected. These are the 351st and 352nd performances of this revival of “My Fair Lady,” for which in-it-from-day-one actors including Harry Hadden-Paton (Henry Higgins), Allan Corduner (Colonel Pickering) and Linda Mugleston (Mrs. Pearce) had to make room for formidable new scene partners.

“Any sort of routine or straight road is altered by this,” says Hadden-Paton, an Englishman who left the show for four weeks in the fall to shoot the movie version of “Downton Abbey,” in which he reprises his part as Bertie, husband to Lady Edith. Upon his return, he and Benanti, lacking substantive rehearsal time, essentially made each other’s acquaintance onstage.


Danny Burstein (Alfred P. Doolittle) and the cast perform “Get Me to the Church on Time” in “My Fair Lady.” (Chris Sorensen for The Washington Post)

“These two people were meeting for the first time!” Benanti recalls — of Henry meeting Eliza at the same moment Harry meets Laura.

But now, more than two months later, the production exudes that sense of deft suaveness customary to the genteel age that “My Fair Lady” — based on George Bernard Shaw’s “Pygmalion” — epitomizes. The amount of finery required to maintain this magnitude of refinement is itself awesome: 10 people employed as dressers and two as full-time stitchers to handle more than 300 costumes for a cast of 37. Those outfits include 30 top hats, 45 shirts, 55 pairs of gloves, 95 pairs of shoes, 100 pieces of custom-made jewelry — all made up of 750 kinds of tones and fabrics. Designer Catherine Zuber’s transformational ball gown for Eliza alone was assembled from sequins, crystals and beads numbering in the tens of thousands.


Christian Dante White (Freddy Eynsford-Hill) watches from offstage before going on for the Ascot scene. (Chris Sorensen for The Washington Post)

Laura Benanti readies herself for the final scene of “My Fair Lady.” (Chris Sorensen for The Washington Post)

In the ample wings of the Beaumont, and in the narrow catacomb under the orchestra seats known as the “Vom” (after, yes, the Roman “vomitorium”), Benanti is whisked out of one costume and into another. Knee pads come flying off, corsets are laced and unlaced, wigs righted and capes fastened. In one rapid sequence, in which the turntable-townhouse set swirls and Higgins’s housemaids and butlers sing about the elocution task that “poor Professor Higgins” has taken on, Benanti quick-changes four times.


Laura Benanti relaxes and stretches during intermission of the evening performance of “My Fair Lady.” (Chris Sorensen for The Washington Post)

The backstage chatter, though, is of the temperature of the crowd. Matinee audiences (mainly tourists) are different from Friday night audiences (exhausted), which are distinct from Thursday audiences (energized). “They’re really good,” Benanti says of this Saturday afternoon audience. “They don’t seem really theater-y. They’re listening and laughing and getting everything.”

Benanti is so in her element as Eliza — the Lerner and Loewe songs seem so effortlessly delivered, it’s as though at times the score sings itself — that her sense of pleasure is relaxing amid the hubbub. The addition of these new performers has had a salutary effect on the original cast members, too. “Acting is all about reacting,” the genial Corduner explains. “So it means your performance has to change.”


A scene during a matinee performance of “My Fair Lady.” (Chris Sorensen for The Washington Post)

At 91, Rosemary Harris handles her comic scenes as Henry’s long-forbearing society mother with the same audience-relaxing security Benanti brings to “I Could Have Danced All Night.” Backstage, she huddles with Hadden-Paton and giggles with Corduner, awaiting only the aid of an arm for an entrance. It was at the urging of her daughter, actress Jennifer Ehle, that Harris agreed to succeed Diana Rigg in the production. And if you ask an actress in her 10th decade what it’s like to be in her first musical, she will respond with an inquiry of her own.

“How do you measure fun?” she says.

“She’s why I signed up to do this,” Danny Burstein says of Harris, as he stands at his dressing room door with teeth begrimed and eyebrows thickened by pencil for his big numbers as Eliza’s rascally father, Alfie. Burstein, who replaced Norbert Leo Butz, is Alfie for only a few months before he starts rehearsals for another Broadway turn, as impresario Harold Zidler in the new stage version of “Moulin Rouge!”


The cast comes offstage after their encore at the Lincoln Center Theater in New York. (Chris Sorensen for The Washington Post)

In the dark recesses of set pieces yet to be rolled on and illuminated, Benanti waits, a mask of professional composure, for her next entrance. Mugleston, who plays Mrs. Pearce, the Higgins household major-domo, with a Scottish accent, waits with her at one interlude in Act 2. They whisper to each other; Mugleston attempts to deal with a pesky wrinkle on Benanti’s dress — Mrs. Pearce to a T. Are they talking over the scene? Nah. “We just kind of shoot the breeze, catch up on each other’s lives,” Mugleston says.

The office water cooler exists even in the wings of a great theater, and signs of everyday life beyond the audience’s vision compete with the progress of the musical. Hadden-Paton appears at his dressing room door with a small tower of pizza boxes, an indication of a visit backstage by his young daughters. A member of the ensemble, Rebecca Eichenberger, hurries down a hallway, stopping to tell a visitor of the tradition of “underdressing,” whereby cast members late in Act 2 wear their street clothes under their costumes to make for a faster exit out the stage door at evening’s end. And as she leaves the stage to boisterous applause after singing “Show Me,” Benanti pauses at the sight of the seated Harris, on whom she plants a kiss.

But it’s Christian Dante White who manages the most exuberant summary of the beehive life of a big musical. Finishing Freddy’s trademark socko song, “On the Street Where You Live,” he appears in the Vom, still vibrating from the audience’s ovation. He points at a friend in the ensemble and exclaims: “That’s Broadway!”