It requires someone with a very long memory to recall New York City Ballet without Kyra Nichols as a shining beacon of excellence and artistic integrity. For 33 years, she has graced the stage with performances marked by her musical sensitivity and subtle interpretive gifts. At the same time, she has always maintained a graciously modest demeanor, drawing attention to the nuances of the choreography rather than to herself.

She has spent fully two-thirds of her life performing at the New York State Theater — dancing virtually every major ballerina role in the Balanchine repertory while also delivering nuanced new shadings to many ballets by Jerome Robbins (who created a number of memorable roles for her), and inspiring choreographers from Peter Martins to Susan Stroman to make ballets that showcased her technical brilliance while expanding her expressive potential.

As the daughter of former NYCB dancer Sally Streets, Ms. Nichols had ballet in her genes, and it was clear early on that she would follow in her mother's footsteps. She grew up in Berkeley, California; by age four she was taking her mother's ballet classes, and soon was studying and performing alongside her at Pacific Ballet.

She was familiar with Balanchine and his approach to classical ballet from an early age. "My mom taught very much like Balanchine, and loved that style," she recalled shortly before the spring season, speaking from the Princeton, New Jersey, home she shares with her husband, David Gray, and their sons, Joe, 10, and Cameron, 5. "Living in Berkeley, I didn't get to see City Ballet perform. I was exposed to a lot of ABT, Joffrey, and Royal Ballet performances. But since my mom had been in City Ballet, that company always intrigued me."

At 12, she attended the School of American Ballet's summer course (on a Ford Foundation scholarship), returning for the next two years and then staying for the full term. "I was really taken by the dancers, the School — everything," she says. "Even though my mom had trained me in that technique, at the School, everything was faster, the extensions were higher. I thought, I don't have a chance. But I loved to dance so much that I just persevered."

Early in 1974, Ms. Nichols became an apprentice with New York City Ballet; she was not yet 16. She became a full member later that year. At first, she did not compel the attention of Balanchine or Robbins, but did gain an important mentor: veteran Principal Dancer Jacques D'Amboise. "When I got into the Company, I wasn't a favorite of Balanchine, but Jacques saw something in me," she remembers. "He helped me out in class, tried to explain exactly what Mr. Balanchine was saying. It was so overwhelming, going into that studio with all those great stars — you don't catch everything. Jacques cast me in a couple of his ballets and got Balanchine to notice me and start giving me small roles. The first one was leading the fourth movement of Bizet [Symphony in C]. I think Mr. Balanchine could see that I understood, and I didn't need him to direct me. I was picking up on what he wanted, and I was going in the right direction. So he never felt like he had to hold my hand — which I take as a compliment."

In 1978 Robbins created an exceptional role for Ms. Nichols in Verdi Variations that brought to the fore her effortlessly musical phrasing and incandescent technical refinement. The following year, it became the luminous "Spring" section of his large-scale ballet The Four Seasons.

"When Jerry picked me out, it was a complete surprise," she says. "I remember that first day in the rehearsal studio with him, and how we just clicked. I just followed him, and I was able to get the right flow that he wanted. It just seemed very easy. That was a very special part for me, especially when Jerry was alive."

Robbins went on to choreograph often for Ms. Nichols — notably in Piano Pieces, I'm Old Fashioned, and Antique Epigraphs. "All of Jerry's works taught me how to be still, yet have projection to an audience," says Ms. Nichols. "Ever since I was little, I always loved to get into a studio by myself and dance around. And that's sort of what Jerry wanted us to do — we were in our own world up there on stage, and the audience was looking in."

Reflecting on her good fortune at being present while the Company's two founding choreographers were still active, she says, "That whole period with Balanchine and Jerry was such an exciting time. You didn't want to leave the theater, because you didn't know what greatness was going to happen."

Ms. Nichols triumphed in numerous Balanchine ballets. The breadth of her repertory — and the pristine, unhurried attack she brought to the most technically challenging roles — has been remarkable. "A special time for me was when Balanchine was alive and I was dancing Apollo with Peter [Martins], Suzanne [Farrell], and Karin [von Aroldingen]. And dancing alongside Karin in Kammermusik No. 2 was very special. He loved watching that," she recalls.

The landmark 1984 revival of Liebeslieder Walzer gave Ms. Nichols the opportunity to reveal new depth and complexity, traits that were also brought to the fore in ballets such as La Sonnambula and Robert Schumann's "Davidsbündlertänze." Peter Martins created several roles for Ms. Nichols that also extended her range in important ways. "It was interesting how Peter was the one who tapped in on my more emotional and dramatic side when he choreographed Poulenc Sonata and A Schubertiad," Ms. Nichols says. "I think that's another reason my career has lasted so long: I've had other ballets beside the highly technical ones I could go into and dance gracefully"

Ms. Nichols did not hesitate to return to the stage after the births of her sons; she had a powerful role model in her mother, who danced into her fifties. But she knew when she was ready to retire. "It just hit me last summer. I felt fulfilled. I danced a lot, I think I've danced well, and I was starting to love being with my family more. I thought, it's time."

Mr. Martins insisted that there be a special farewell program in her honor, and planned what promises to be a memorable, bittersweet evening on June 22. "I said one ballet I would love to dance for my final performance is Serenade, because it was the first Balanchine ballet I ever danced, in the School," Ms. Nichols says. She will also dance Robert Schumann's "Davidsbündlertänze" and the final section of Vienna Waltzes. And then we will be left with our decades of indelible memories, and she will be spending time with her family and teaching fortunate students at Princeton Ballet School. Ms. Nichols, who is making her transition with the same graciousness and balanced perspective that have marked her dancing, says contentedly, "I've had such a wonderful career, and I'm leaving at a good time."

Susan Reiter is a freelance journalist who writes about dance for a variety of publications, including New York Press and The Los Angeles Times.