Washington Ballet Artistic Director Julie Kent, right, works with Rolando Sarabia and Eun Won Lee in rehearsal. (Bill O'Leary/The Washington Post)

Julie Kent, the new director of the Washington Ballet, watches intently as one of her dancers soars. The dancer’s shoes squeak on the floor as he spins, and sweat flies off his face. Music booms from a sound system in the corner. Victor Barbee, the company’s associate artistic director and Kent’s husband, calls out timing cues and encouragement. But Kent, who is perched on a stool at the front of the studio, her back to the wall of mirrors, is the quietest person in the room.

She is motionless as she studies Brooklyn Mack, her spine erect, her hands rolled up in the hem of her purple T-shirt. On this recent afternoon at the company’s headquarters on Wisconsin Avenue NW, Mack is wheeling through the air, circling and bounding at top speed in this rehearsal of a high-spirited excerpt from “Don Quixote.”

Just a couple of weeks into her tenure as director, Kent is overseeing preparations for the Washington Ballet’s 40th anniversary celebration. It’s a one-night affair Friday at the Kennedy Center’s Eisenhower Theater, with two complete ballets and sections from four others, such as the “Don Quixote” grand pas de deux that Mack is rehearsing.

A lot is riding on this single evening. Kent must pay homage to her predecessors — Washington Ballet founder Mary Day, who died in 2006, and Septime Webre, Day’s successor, whom Kent has replaced. She also must honor the history of the company with which she has only recently become acquainted.

Most important, Kent must send a strong signal about the company’s future. This event will offer the first look at how Kent, 47, a former star of American Ballet Theatre, intends to change the Washington Ballet.

Mack launches into the air and spirals above the floor. He finishes by gliding to one knee, soft as a cat. His arm swings overhead in a crisp flourish as the cymbals clash from the speakers. Then he doubles over, sucking air. His eyes shift to Kent, to the floor, back to Kent. Chest still heaving, he waits. And waits.

Kent bows her head in thought. Or is it disappointment? There’s no telling what’s going through her mind. She may be mulling how this dancer and this brief showpiece will help her change the look of the company she has taken over from Webre, who led it for 17 years. A choreographer known for high-energy, even raucous productions, such as his “Alice (in Wonderland)” and “Carmina Burana,” Webre stamped the Washington Ballet as a showcase of youthful punch and audience-friendly showmanship.

Kent, who retired from ABT in 2015 after an extraordinary career as one of this country’s most accomplished classical ballerinas, has a different view. She aims to groom the Washington Ballet in the more refined, elegant language of the classics and first-rate contemporary works. Her 2017 season includes her staging of the romantic-era ballet “Giselle” and ballets by 20th-century British masters Frederick Ashton and Antony Tudor.

She has a ballerina’s eye for subtlety and detail, and for the small charms that can captivate and hold an audience.

Everyone in the rehearsal studio grows still. Mack, his partner Maki Onuki, the understudies, Barbee — all wait in silence. Finally Kent rises from her stool.

Will she praise the height of Mack’s jump or correct some aspect of his pirouettes?

She reaches for his hand. She says nothing about his dancing. “Let’s fix your fingers,” she says, her voice barely above a murmur. Mack re-creates his kneeling pose, with one arm lifted. Kent molds his upraised hand like a sculptor working clay, softening it, curving it and slightly separating his fingers.

She examines it from every angle.

“This is how it should look,” she says, settling back onto her stool. “If I was going to draw it, I would have a study of your hand.”

It’s the smallest feature of his performance, perhaps, but Kent knows that Mack’s hand, the one he sweeps overhead as he lands his series of leaps, is what the audience’s eyes will rest upon.

Washington Ballet Artistic Director Julie Kent, center, shares a moment with some of her dancers, from left: Brooklyn Mack, Eun Won Lee, Rolando Sarabia and Maki Onuki. (Bill O'Leary/The Washington Post)

In dance, the beauty happens by degrees.

Kent and Barbee don’t have a lot of time for the details. At the end of the summer, they left their jobs at ABT, where, after retiring as a ballerina, Kent became artistic director of the summer intensives and Barbee was the longtime associate director of the company. They moved with their two young children to Washington, where the kids started new schools and their parents plunged straightaway into rehearsals as well as the thicket of administrative tasks surrounding the anniversary program.

Then there’s the rest of the 2016-2017 season to nail down, and planning next year’s season. The upkeep of the aging company headquarters is also on their minds. Kent and Barbee are mulling installing ceiling fans, to cool the studios enough to turn off the inconstant air conditioning, which sends the dancers into an uncomfortable cycle of chills and sweat.

“It’s endless,” Kent sighs, as she sips water in her office. Her laptop is propped open on an antique writing table with glass drawer knobs — “my little ballerina desk,” she calls it. Other ballerina touches: a line of colored perfume bottles on the shelf of her lavatory, and photos of her and Barbee and other ABT dancers against the walls, waiting to be hung.

“In this transition there are so many things that I would love to make sure don’t fall through the cracks,” she says.

“Everywhere I look, it’s unknown.” She feels she hasn’t spent enough time with each of the dancers yet to truly know them and their strengths.

Julie Kent works with dancer Maki Onuki during rehearsals. (Bill O'Leary/The Washington Post)

Julie Kent with her husband, Victor Barbee. (Bill O'Leary/The Washington Post)

“It’s a process of working with them all in order to discover how best I can use them, how I can help develop them, what they need more of, what are the things they need to work on.”

But what she has seen so far, she says, gives her hope.

“What we found so rewarding is how quickly they’ve absorbed the comments, and how in a matter of days it’s really come so far,” Kent says. “But that’s dancers. We spend our whole lives applying corrections and details and thought. It’s not like you do it well and you’re done, and ‘That’s how I do this role.’ You have to build on it each day. It’s a life’s journey.”

Kent knows about the long view of a career — she danced with ABT for 29 years — and that uncommon depth of experience is likely to be one of her greatest assets as a director.

“In a company this small you can’t be one dancer in three different costumes, you have to be three different dancers,” she says. “And that’s really rewarding, but not everybody can do that. So you have to help them understand that idea, that it’s not enough to be you — you have to develop the entire performance.”

Kent hopes her three new hires will help set the tone. Rolando Sarabia, 34, was a principal dancer with the Ballet Nacional de Cuba and a guest star in many companies. Eun Won Lee, 25, was a leading ballerina with the Korean National Ballet, who so idolized Kent that, knowing very little English, she left her family and homeland to move to Washington.

Julie Kent, center, with dancers Rolando Sarabia and Eun Won Lee in rehearsal. (Bill O'Leary/The Washington Post)

“She’s so beautiful, even when she doesn’t move a lot,” Lee says of Kent, speaking through a translator. “She’s so graceful and noble inside.”

“That’s serious commitment, and a reflection of the vested interest in this company,” says Kent, who praised Lee’s “conviction and determination in contrast to how delicate and long and feminine she is. It’s a wonderful contrast that is so useful in classical ballet and romantic ballet. You need to have the power along with the femininity and grace.”

Brittany Stone, 24, left the corps of Boston Ballet to join Kent, whom she had known while training at ABT’s Jacqueline Kennedy Onassis School. Kent, at the height of her stardom, would sit and chat with the young student and her family in the ABT hallways, and remained a mentor to Stone as she grew into a professional dancer.

These dancers were attracted to Kent as an iconic ballerina and a sensitive and respectful collaborator. But no one knows yet what kind of director she will be.

At this early stage, it is evident that Kent is perceptive, methodical and patient in the studio. And she is eager to make her mark in a broader way than just one night’s performance. “What I don’t feel like I have the time yet to do, is make a difference for the entire community, for this whole Washington area to feel like it’s getting all of our attention and effort, and to feel that support. And to see it in the audience and feel it in the air. . . . You just hope everybody else is going to push it forward, too. Because Victor and I can’t push it to a new place just the two of us.”

Back in the studio, Mack and Onuki are leaping side by side in the “Don Quixote” excerpt. But Kent sees that they are slightly out of sync. She wants them to match each other step for step, with perfect timing.

“It’s a little thing, but it looks magical when you see it,” she says.

They slide, jump, skim and spin again.

“Yeah,” Kent says, almost in a whisper. “I’m very happy with that.”

Barbee turns to his wife. “I think it’s enough.”

Kent is silent for a moment, considering.

“Yes,” she says, at last, with a hint of regret. Perhaps she’s wishing that she could linger over the details.

“I do, too.”