It is to Cynthia Harvey's credit that her debut as the Swan Queen in American Ballet Theatre's "Swan Lake" at Kennedy Center's Opera House Sunday afternoon was so nearly a finished performance that one wanted it to be completely so. Harvey's enchanted-Odette was better danced than her enchantress-Odile, but less interesting.

As Odile, there was a marvelously nasty undertone to the coldly scientific curiosity with which she watched the effect of her wiles on her victim. Her tense, wild-creature Odette was notable for its beautiful line and proud arabesques and will undoubtedly soften a bit as she relaxes in later performances. As Prince Siegfried, Ross Stretton was the partner every debutante must hope to have -- strong, supportive and unobtrusive. Only in his cleanly danced third act solo did Stretton grab the stage for himself.

Magali Messac's magically mysterious Odette-Odile at the Saturday matinee was also a debut. Messac converted the newly-restored second-act mime scene into gesture, but danced with lyric warmth in the "white acts" and tempestuous strength in the "black" one. Victor Barbee, yet another promising weekend debutant, danced a Siegfried that was at once nervous and grand in scale.

On Saturday evening, Cynthia Gregory and Alexander Godunov gave the kind of performance that only experienced dancers can. At the end of the second act, when Odette is transformed from maiden into swan, Gregory fought with every ounce of her considerable strength, the transformation wracking her body. As Odile, her rock-steady fouettes were but one example of a performance that was technically perfect. Godunov always looks cramped on the Opera House stage -- he doesn't have room to complete his jumps. He and Gregory have been less than sympathetic partners in the past, but on this occasion they were completely in sync.

Throughout the weekend, the corps, whether as swans or members of the new Von Rothbart Travelling Folk Dance Troupe, was occasionally ragged, but always danced with flair. Christine Spizzo, Kristine Elliott and Leslie Brown gave particularly notable performances in assorted pas de trois.