AT HER PEAK: Ballerina Cynthia Gregory, shown here as Odile, the black swan in “Swan Lake,” during her career with American Ballet Theatre.

In a classroom at the Princeton Dance and Theatre Studio in Forrestal Village, six young men take their places and wait for music from the ballet Raymonda to begin. Sitting in front of them with her back to the mirror is a woman who was dancing “Raymonda” — and just about every other ballet in the classical repertory — before they were born.

Watching Cynthia Gregory demonstrate how to use a plié, or deep knee bend, to add spring to a jump, or how to open the arms into a more authoritative pose, it seems as if she might have performed these movements yesterday. Yet it has been two decades since this famous ballerina retired from dancing after a stellar, 26-year career with American Ballet Theatre (ABT).

These days, Ms. Gregory spends much of her time coaching younger generations of dancers. For the past several years, she has traveled to Princeton from her home in Las Vegas to Princeton Dance and Theatre Studio’s annual Summer Intensive. For one week, she works with the students on the finer points of performance. The 48 students in this year’s program come from several states and Guatemala. In addition to Ms. Gregory, they studied this summer with former ballerinas Susan Jaffe and Kyra Nichols; and with Roy Kaiser, who is artistic director of the Pennsylvania Ballet. The students will give an end-of-term performance Friday, July 27, at 1 p.m. at The Hun School Auditorium. Tickets are $10.

“I like to coach, rather than teach. There are so many better teachers than me,” Ms. Gregory says. “I like to work on the art of dance rather than the nuts and bolts. And they already know what they’re doing when I get here, so I can work on the finer points with them. The students here are very strong. There are no watered-down versions of anything. They’re learning the real thing.”

For Risa Kaplowitz, co-founder of the school, hosting Ms. Gregory each summer is a thrill for the students, and for her. “This is Cynthia’s fourth or fifth time at PDT, and I am still in awe of what she offers the students,” she says. “Her coaching is filled with positive energy and her simple explanations for difficult steps can make such a big difference in how a dancer executes them. Most of all, she gives the variations context and inspires the students to dance them with joy.”

A much younger-looking 66, Ms. Gregory has a warm smile and open manner that seem to put the dancers immediately at ease. She is quick to offer encouragement while pushing her charges to work harder and reach for a level that transcends technique and athleticism.

“The level of technique today is fabulous. It’s amazing,” she says, speaking of ABT, where she spent her career. “But the general feeling is more bravura than drama. Somehow, the heart is gone. We didn’t have that level of technique, but we had something else. I try to pass along what I learned from people like Agnes de Mille, whom I loved. She taught me how to be a real person on stage. I tell the dancers today to be real with their gestures, to be themselves. That translates to the audience.”

De Mille is only one of the renowned choreographers with whom Ms. Gregory worked during her long career. Born in Los Angeles, she began studying ballet as a small child. She managed to get herself into a class that George Balanchine was teaching when she was only 13. The great choreographer and co-founder of the New York City Ballet was impressed and invited her to come study in New York, but she was too young.

A year later, though, she was accepted into the San Francisco Ballet as an apprentice. Her parents sold their home and business and the family moved to San Francisco, where Ms. Gregory thrived. She stayed with the ballet company for four-and-a-half years before deciding to make the move to New York. Since Mr. Balanchine had encouraged her, she expected to join his company, where abstract ballets tend to dominate the repertory.

“But I saw a performance by ABT, and I set my heart on that,” she says. “It was drama. I like to tell a story, and that’s what they were doing. It’s not that I don’t love the Balanchine repertory; I do. But the story ballets suited me best.”

ABT had Giselle and La Sylphide in its repertory when Ms. Gregory joined. Over the years, more full-length classics and ballets by Agnes de Mille, Antony Tudor, Jerome Robbins, and other choreographers were added. “I just fell in love with all of those ballets. They kept adding more, every year or two,” Ms. Gregory says. “I could really immerse myself in the roles.”

While drama was her forte, Ms. Gregory was also a formidable technician. She was known for her ability to balance en pointe longer than just about any other dancer, and her fans loved her for it.

She especially enjoyed working with Mr. Robbins, performing his ballet Other Dances with Alexander Godunov and Kevin McKenzie, now ABT’s artistic director. “He showed another side of me,” she says of the choreographer. “A lot of people never thought of me in that way.” Mr. Robbins was her favorite choreographer. But he was a tough taskmaster. “He made you do things over and over, and I get worse as I do things over and over,” she says. “Twyla [Tharp] was like that, too.”

Ms. Gregory exited ABT during the period that Mikhail Baryshnikov was artistic director. The Russian superstar favored younger dancers. Only in her mid-thirties, which is considered a dancer’s prime, Ms. Gregory chose to bow out. “I didn’t thrive under him, so I started doing guest performances,” she says, tactfully. “I did get to dance with him once, in Balanchine’s Prodigal Son, and that was great. But I needed to move on.”

When Ms. Gregory ended her dancing career a few years later, she was ready. “I don’t miss it,” she says. “I was really completely fulfilled.”

She has been divorced twice and widowed once. Ms. Gregory raised her son, now 24, in Greenwich, Connecticut. She moved a few years ago to Las Vegas, where she is an artistic advisor with the Nevada Ballet Theatre. She coaches for that company and elsewhere.

“I’ve been very fortunate,” she says, flashing her radiant smile. “I had no major injuries. I got to  work with the most amazing choreographers in the world. And now I get to pass it on.”