Because the Capitol Ballet is locally unique - as one of the rare dance institutions across the country dedicate to affirmative action with respect to opportunities for blacks in ballet (though the company is fully intergrated) - it is important that it flourish, both for the art and the people it serves. The occasional fallow periods, such as it currently seems to be undergoing, must be looked upon as unrepresentative.

The troup's weekend performances at Lisner Auditorium mirrored the effects of recent internal upheavals, resulting in the loss of principal Sylvester Campbell and other personnel.

Even the presence of the guest artist - Hinton Battle, Lydia Abarca and Kelvin Coe - could not obscure the company's depleted condition. For the most part, the dacing raw and ill-coordinated, and though several youngsters give signs of promise, only ballerina Sanda Fortune presently has anywhere near a developed techique.

Unfortunately, this leaves Fortune so isolated that she's left to do only showy pas de deux that don't always display her to best advantage - she needs to be dancing in ballets, not bravura excerpts. Desptite some praise-worthy passages, her "White Swam" Adagio looked labored and flat, and a broadly, badly revamped "Don Quixote" pas de deux was humdrum. The dancing by guest artist Coe, her partner, was intermittently flashy but artistically gauche.

It did not help that neither of two new pieces by company co-director Doris Jones - a diffusely ritualistic "Antiquities," and a tasteful but inertly academic "Unfinished Symphony" - proved effective.

Guest artist Honton Battle, himself a Capitol Ballet alumnus, provided an oasis of sparkle in his own brief but crisly impudent "Overture," to the music of Joplin. But it remained for Doris Jones' engagin, smartly contructed version of "Rhapsody in Blue" to remind us of the company's finest past moments. The patrician Lydia Abarca danced beautifully, even if her silken fluency looked a bit too decorous for the context. Leroy Cowan was her able partner, and Battle again brilliant in his solo.