Thirty-four years after its creation, Jerome Robbins' "Interplay" is a lively period piece. It's a plotless ballet about a type of kid that didn't survive the '50s -- the kid in pony tails who turns cartwheels, plunges into amiable competition and slinks sexlessly through a pas de deux. The New York City Ballet presented the season's first performance of "Interplay" last night at the Kennedy Center and its cast of young dancers gave an energetic and good-natured performance of a work that, if its characters are a bit dated, is still good, clean fun.

The ballet is still interesting to watch because Robbins' construction is solid. In this, his second ballet, he began to define his version of "American classicism," which flowered in his later "Dances at a Gathering" and "Goldberg Variations." The dancers in "Interplay" engage in technical high jinks, romping and spinning around the stage. Last night they were appropriately spirited, if occasionally imprecise. Sandra Jennings and Christopher Fleming danced the pas de deux smoothly and Lourdes Lopez and Jean-Pierre Frohlich best caught the spirit of the work.

The program was completed by a flat performance of George Balanchine's beautiful, icy "Chaconne and one of his crowd-pleasing Broadway ballet "Vienna Waltzes" in which all of the principals were ravishing.