This "Nutcracker" asks the question whether a girl can become a ballerina while wearing her nightie. Everyone else at the castle is dressed so as not to be an embarrassment in front of swell friends. Even the hero sheds his stiff breast plate and grotesque Nutcracker helmet with the huge jaw piece to become a cavalier. Clara, the heroine of Mikhail Baryshnikov's version of the Christmas ballet at the Kennedy Center, is the only figure clad in something ordinary -- a pink shift.

This nighgown bunches at the shoulders and creates the illusion of a hump. It hides the filigree legwork. Its dowdiness makes the culminating act as awkward for Clara as one of those absurd nightmares in which the dreamer alone is naked amidst an attired throng.

To cope, the three American Ballet Theatre soloists who were cast as Clara at Kennedy Center on Christmas and at the two Boxing Day performances were forced to project character every instant. They did not achieve the nirvana of graciousness and grandeur that befits a classical role. Ballerinadom may be an impossibility given Baryshnikov's psychological conception and the merging of the Clara and Sugar Plum parts, but a tutu instead of a nightgown just might have helped to satisfy those expectations established by Tchaikovsky's music.

Cynthia Harvey and Ross Stretton, making their debuts as Clara and the Nutcracker Prince on Friday afternoon, acted as if they were Juliet and her Romeo. It was a shrewd notion. Stretton's wry features suggest ardor and youth's perpetual surprise. Harvey played eargerness against hesitancy in company and, alone in the dark, was more disgusted than frightened by the mice. At the end she restored that Antony Tudor touch of frustration as she faced a future without the lover of her dreams.

Up to that ending, Harvey and Stretton had been the consummate lovers, sailing into the air and landing like feathers. Their dancing showed off their long bodies and emphasized the choreographic line. Harvey has trouble in balance turns, but managed to center herself most of the time. The male solos were set by Baryshnikov with himself in mind. More important than line are mercurial dynamics and sudden changes of directions without transistions or rests. Such things are problematic for streamlined dancers and Stretton played them down suavely.

Kevin McKenzie also is tall, slim and unsuited for swordplay dancing. In his debut as Nutcracker on Friday night, he didn't gloss over the flashing footwork, sometimes moving with full force but at other times seemingly tied to the ground. In manner, McKenzie was gracious, presenting hinself and partnering Leslie Brown like a true Petipa danseur.

Leslie Brown is a movement actor. Classical dancing has been hard for her since her last return to ABT from the movies. In tutu roles, her upper body congeals at odd angles as she bites into the pace of a piece, refusing to let go with a terrier's determination. For the part of Clara, the nightie actually helped Brown's body placement. Her Alice-in-Wonderland characterization was totally winning.

Rebecca Wright and Danilo Radojevic, the leads in "Nutcracker" on Thursday night, are two of the dancers who have changed for Baryshnikov's new regime at ABT. Wright used to resemble Bette Davis. She's no longer a gaunt, frantic virtuoso. A few pounds a sedateness have made her comely and classical. Her first Clara this season, though, was boringly danced. Looking and acting like Gelsey Kirkland, Wright's way with the remarkable Kirkland's impetuosity rang false. Radojevic, short and compact like Baryshnikov, came closest to the title role's physical demands. He no longer mangles movement to achieve forceful effects, though more lightness would be welcome.

Subsidiary parts in "Nutcracker are giving ABT performers chances for small triumphs or tribulations. Among the winners was ballet master Jurgen Schneider in unscheduled appearances as the tipsy guest who becomes the Mouse King.