Misty Copeland in an American Ballet Theatre production of “Romeo and Juliet.” (Rosalie O’Connor)

To every ballerina, at every age, a different Juliet. The role of Shakespeare’s spitfire who rocks Verona and pays for love with her life offers endless fuel for a dancer’s imagination, no matter how many years, or even decades, she may have already spent soaring across the stage in Romeo’s arms.

The heroine of “Romeo and Juliet” is the rare ballet role that can bookend a career. A budding star of 20 may imbue her first Juliet with tenderness and optimism, while at 40 or 50 (or even beyond) she might bow out with a Juliet who is fierce and sexual and doesn’t blink at death.

This variability is especially apparent in the oceanic, three-hour version of the ballet created by Kenneth MacMillan, which American Ballet Theatre will perform July 14-16 at Wolf Trap, marking the company’s first appearances at the outdoor venue in 31 years. Accompanied by the thundering, weeping Prokofiev score, MacMillan’s ballet makes plain the raw emotions and cruelty that doom the young lovers. Since the ballet’s premiere in 1965, the greatest ballerinas of the age have embodied MacMillan’s Juliet: Margot Fonteyn, Lynn Seymour, Natalia Makarova and Alessandra Ferri — who, by the way, just last month returned to it at an astonishing 53.

Unlike the more technically demanding heroines of “Swan Lake,” “The Sleeping Beauty” or “Don Quixote,” Juliet welcomes a vast range of interpreters. She does not bowl us over with pirouettes and steely balances. Her art is on a human scale, although she must project at an operatic pitch, communicating her inner world to the upper balconies even in several key moments when she is frozen in thought, not moving a muscle.

Three Juliets will perform at Wolf Trap, each at a different stage in her career. Hee Seo, 30, has been dancing Juliet since she was 23. (She will lead the cast July 14, with Cory Stearns as Romeo.) Misty Copeland, 33, made her debut in the role just a year ago. (She will perform July 15, with Joseph Gorak.) Gillian Murphy, 37, is celebrating her 20th anniversary with ABT and has inhabited Juliet for nearly a decade. (She will dance July 16, with James Whiteside.)

What is it that makes the role of Juliet so prized, so formidable and so much fun to dance? Three longtime Juliets — Murphy, Ferri and Julie Kent, who danced the role at her farewell to ABT last year — reflect on their revelations in exploring the life, and death, of the immortal Renaissance teenager.

The power of stillness
Dancer Gillian Murphy in “Romeo and Juliet.” (Rosalie O'Connor)

For Gillian Murphy, a technical powerhouse with an affinity for speed, the hardest part was learning to be still.

“As Juliet, you have to really slow it down, and process things,” she says. “The emotion in Juliet is more visceral, more raw, more of just standing there and feeling it.

“There’s a real power to that stillness and to letting the music serve an internal world, rather than having Juliet flail around.”

Murphy says that a crucial first step to feeling comfortable as Juliet was learning the lead role in the 30-minute masterwork “Pillar of Fire,” a compressed interior drama by Antony Tudor, from 1942, about a young woman’s sexual awakening, her public shaming and her unexpected salvation. Tudor, who was British like MacMillan, worked in a vastly different style from the “Romeo and Juliet” choreographer, yet he also favored emotion, drama and naturalistic action over showy feats of strength.

“It started with ‘Pillar of Fire’ that I felt stretched in that direction, and I started redefining myself, in a way,” Murphy says. “Seeing that ballet steps really could have more intention and more of a dramatic impulse, and that’s particularly crucial when you’re playing a role like Juliet, where it’s all about her journey, and her journey with Romeo.”

She pauses, sorting her thoughts. “I don’t want to throw technique under the bus here,” she says with a laugh, “but dancing Juliet brings out a different side of me, because the choreography allows a dancer to fully immerse herself in the role, rather than (A) either worrying about technical elements or (B) about razzle-dazzling the audience in a way that might be distracting them from the emotional journey.”

“It’s also particularly interesting in the Instagram culture, which I’m a part of,” Murphy added. (That’s putting it mildly; eminently photogenic, with a witty, artful curatorial eye, she has north of 56,000 followers.) “The pirouettes and contortionism become what people are looking at and are drawn to. It’s harder to capture artistry on Instagram. That’s one of the reasons dancers are so drawn to Juliet, because it’s artistry that you can’t quantify.”

Don’t be afraid ‘of being ugly’
Alessandra Ferri in “Romeo and Juliet.” (Fabrizio Ferri)

Alessandra Ferri first danced Juliet when she was 19, coached by MacMillan himself. The Italian phenomenon was the youngest principal dancer of the Royal Ballet, where MacMillan was principal choreographer and where he had initially created the ballet. He told her, “‘Darling, don’t you ever be afraid of being ugly onstage.’”

“Kenneth was not a romantic,” Ferri says. “He was very down to earth and interested in all the psychological aspects of life, and even the violence of life.”

“Juliet is flesh and bone, and what she and Romeo have is not romantic puppy love. They were ready to jump into each other’s arms, sexually. They couldn’t wait to experience all of that.”

The ballet is not a soft-focus treatment; it is marked by death, abandonment and betrayal. “You can’t convey that by being pretty,” Ferri says.

But how does a ballerina do ugly onstage? “By getting rid of all the ballerina aspect,” she replies. “You’re a human being. You’re not acting your way through it. You have to stop looking at yourself as a ballerina.”

As an example, she points to scenes with Juliet’s nurse, or with Romeo, where she has to be a little brutal to convey the urgency of her feelings. “Instead of just caressing them gently with your ballerina hands, you grab them. You have to be real. Don’t be afraid of strength, force, sexuality.”

Ferri was speaking just days before her June 23 performance as Juliet in New York with ABT, and with Herman Cornejo as her Romeo. She is famed and beloved for the role around the world, and she described it as “my second skin.” Yet that is what made it difficult to step into at 53, nearly a decade after she last danced it.

“I have a very clear memory of how I felt in it when I was younger, and I was intimidated by my own memory. I had to let that go, and ask, ‘What is true for you now?’ ”

She decided to perform Juliet again because “I wanted to make sure that I enjoy my life to the last moment.”

“Maybe I need more work than when I was 20, but I have more depth,” Ferri says. As an older dancer, she has learned something exquisitely simple: “not to perform, but to be present. Just to be. To be present with the whole of yourself. It’s an inner faith I’m talking about.”

What also guides her is courage, which she expresses in a way that sounds very Juliet: “Don’t buy into what anyone else is thinking. We don’t live our lives for other people.”

‘Makes you feel forever young’
Julie Kent in “Romeo and Juliet.” (Rosalie O’Connor)

Julie Kent retired after a performance of “Romeo and Juliet” last summer, at 45, after 29 years with ABT. In the months leading up to her new role as artistic director of the Washington Ballet, she has been coaching younger ABT principals. The key, she says, is realizing that Juliet is not alone.

“You’re not the only one telling the story, and yours isn’t the only story on the stage,” Kent says. “I always encourage the Juliets I work with to use everyone on the stage. You’re not in a box. You’re living and responding to the action on the stage. That kind of interaction between the characters is what creates a real sense of spontaneity and life, when everyone is really telling the story together.”

The difficulty, though, is that when a ballerina is rehearsing Juliet with her partner and their coaches, the full cast is seldom in the studio with her. “The only way you can take it to the next level is by performing it more,” Kent says. “It’s only with real experience, and the chance to make the discoveries in the performance, not in the rehearsal room.”

Juliet is one of her favorite roles, but not because it is pure pleasure. Dancing Juliet is a bittersweet sensation, she says; the arc of the story plunges the ballerina into despair as well as joy. For the dancers, as all three of these ballerinas have attested, the choreographed turmoil feels real, and recovering from the experience can take a few days.

When Kent stepped into Juliet’s world for the last time, 23 years after her first time, the experience felt new and wonderful and horrible all over again.

The young lovers “represent the hope of all of us, and then it’s shattered innocence, the crush of the optimism of young love. And it gets to all of us. It’s almost perfect, almost solving all the problems of the world, and then it doesn’t. And that feeling is eternal. That feeling is still so fresh, and it makes you feel forever young.

“When you are Juliet, you are so in tune with the possibility of what is to come, and how beautiful that is. You’re so close to those thoughts and that idea. And that was probably the revelation: the greatness of that story and what it means to all of us, because you believe it. It’s so beautiful and so hopeful — and then it’s gone.”

American Ballet Theatre will perform “Romeo and Juliet” at 8:30 p.m. July 14-16 at Wolf Trap’s Filene Center. Tickets $20-95. www.wolftrap.org.