"THEME and Variations" took stamina to dance, and the weeks of rehearsals had been rigorous. Now the floor of the Kennedy Center Opera House stage, bathed in light, awaited him -- and an audience of more than 2,000. Would he panic, he wondered, or take to it like it was the American Ballet Theatre rehearsal hall back in New York?

In the wings last Sunday afternoon, Ronald Perry was preparing to dance his first principal role in the ABT run here. With minutes to go, Mikhail Baryshnikov, the ABT's artistic director and the man who had given Perry a chance at the plum role, approached Perry and promised him a champagne at the end of the performance if he did it well.

It was just the little bit of extra adrenaline Perry needed. He moved onto the stage, feeling naked in his tights. A little nervous. But he began to psych himself into feeling that he was alone in his studio, dancing to please himself.

When it was over -- relief. A small triumph.

On his dressing room table, Perry found a bottle of champagne with a card from Baryshnikov. He never drank it. "I don't drink," he said. "I gave it to my roommate."

After 11 years with Arthur Mitchell's Dance Theatre of Harlem, learning the craft of dance and perfecting the technique, Ronald Perry, 25, is one of the newest dancers in the ABT corps de ballet, striking out in a principal role -- as are many in the corps this season -- to critical commendation. One critic declared him "outstanding" despite "minor laspses in technique."

The company, currently in its season-opening four-week engagement here, has only two blacks and Perry is one of them. "I really don't know what to say," he said smiling and bewildered when asked if the distinction makes him feel any differently. Classical ballet "is really open," he said. "It's open for people who are capable. It's not keeping blacks out. It may have been a problem in the past, but not now."

At 13, he was quiet, introverted, uninterested in sports or other activities that occupy most children growing up. "My parents were very concerned about me," said Perry, who grew up in Great Neck on Long Island. "I stayed to myself. My mother says when I watched TV and saw dancing, I imitated what I saw." A friend of the family suggested that they let him take dancing lessons and his parents were game for anything that would draw him out.

The family friend took Perry to Arthur Mitchell, who looked him up and down and told him to come back for Saturday classes. "I thought, 'Sure, why not?' said Perry. "It was just exercises for me. My mother and father said just give it a try and see for myself. I guess most fathers would want their sons to be in baseball."

But Perry's mother, a domestic worker, and his father, a chauffeur, were different. Six months later Mitchell offered Perry a scholarship to take classes every day that summer. When fall came, Mitchell suggested that Perry attend Children's Professional School in New York in the morning and go to dance class in the afternoon.

"I didn't really want to do it," said Perry. "I didn't want to leave my school friends. But my father said, 'It's still too soon to tell. You're being impatient." (His father has since died. His mother will see him dance with ABT when the company returns to New York.

After 11 years with the Dance Theatre of Harlem, he auditioned this year for ABT. "I'd always wondered what it would be like to be in another company," he said. "I always felt so protected at Dance Theatre. It was like growing up in a family." When he left, he said, "I think Arthur Mitchell was kind of hurt. But I think he was kind of pleased. He felt it was a good idea for me to get out on my own."

Like any other dancer, Perry lives with the discipline, the pain and the fierce desire to turn the technique of dance into a blaze of moving art on stage.

"With me, it's like every year I want to quit," he said, a picture of grace flowing smoothly from the fine cheekbones of the face through the long arms and the thick, supple legs that move like elastic bands. Gray knit leg warmers up to the waist covered his black leotard and tights. (He said that even his mailman in New York guessed he was a dancer at first glance).

"My body is very strong," Perry said, patting a leg. "It can last a long time. But just about every artist goes through a time when they're very discouraged. When you have a bad performance you feel like it's the end of the world. It's all the process of making you a better artist."

That is what he is concentrating on this year. "When you're training at the beginning, everything is from the navel down. They're so concerned about your legs," he said putting one up on the dressing table next to him in mid-sentence.

"I'm just trying to keep myself as a whole," he said, "a total artist. At Dance Theatre, I would have been picky -- seeing if my feet weren't pointed right. I'm not just feet or legs or arms or head." A wave of the arms punctuated each part.

On the road, he rehearses two hours each day. In New York, where he lives in an apartment, he rehearses six hours on days when there are no performances. "Dancing hurts," he said. "Your legs hurt, your feet hurt from jumping, your back hurts." Then there are his "normal injuries," like the "tendonitis in my Achilles tendon."

"Sometimes you're floating and it's fine," he said. "Other times, you feel like, 'Ohhhh-kay, just get me through this day.' But when you're performing, as soon as you go from the wings of the stage, you've forgotten. It's very rare to feel injuries on stage."

He was petrified at his ABT audition. But he got the job, and of course the part in "Theme and Variations," which Baryshnikov let him do. "The man has faith in me," Perry said. "He doesn't know me yet as an artist."

He rehearsed for three months for this season. "Seven double tours -- it's just not done every day in ballet," he said. Cynthia Harvey danced the role with him at last Sunday's matinee. "She's a wonderful, wonderful person and a wonderful dancer to work with -- and me being a newcomer, she was very gentle on breaking me in," he said. "It could have been more of an ordeal."