Forty-seven years ago this spring, Jerome Robbins began choreographing a new ballet for a troupe he had just formed, Ballets: U.S.A. That work was N.Y. Export: Opus Jazz, and it was an instant hit. When the 16-member troupe performed in New York, John Martin of The New York Times called Opus Jazz "perhaps the best thing [Robbins] has ever done."

The short-lived Ballets: U.S.A. was born as the result of an invitation from Gian Carlo Menotti. Could Robbins, the composer wondered, assemble a fresh-faced group of young dancers to be in residence at the three-week festival that Menotti was inaugurating in Spoleto in the summer of 1958? N.Y. Export: Opus Jazz made its debut in the Umbrian hill town along with Robbins' delicate duet Afternoon of a Faun, his hilarious The Concert, and Todd Bolender's Games.

West Side Story‹the epochal musical created by Robbins, Leonard Bernstein, Arthur Laurents, and Stephen Sondheim‹had opened in New York the previous fall. It's small wonder that the kids of the plotless N.Y. Export: Opus Jazz remind us of the Jets and Sharks. Letting off steam to Robert Prince's jazz-infused score and against Ben Shahn's backdrops, the dancers in their sneakers and casual garb are a sometimes sullen, sometimes exuberant clan, bound together by their youth and "cool"‹swinging their hips, snapping their fingers, challenging one another. Love can seem impossible, and lust provokes a vicious game.

To European spectators, Robbins' gift for melding vernacular movement and breezy, up-to-date manners with classical steps and structures (such as a fugue) was an exciting novelty. When Ballets: U.S.A. returned to tour the continent in 1959, it was with State Department sponsorship. In those Cold War days, art could serve as a weapon against the spread of Communism, and the company brilliantly fulfilled its mission as an envoy of American culture. Wrote a critic for Berlin's Der Tagesspiegel: "None of the illustrious ensembles of the new world has loosened the ties to the classic tradition of Europe like this one and none has more unmistakably turned national mentality into movement."

On the opening night of Ballets: U.S.A.'s first New York season, Robbins received a telegram from George Balanchine and Lincoln Kirstein saying, "Best wishes for the most brilliant success and we only hope that we will be the residual frame for your masterpieces." That hope was later fulfilled, and Kirstein would be pleased to know that N.Y. Export: Opus Jazz, a work he craved for the New York City Ballet from the minute he saw it, has finally won a place there.

Deborah Jowitt is the principal dance critic of The Village Voice and the author of Jerome Robbins: His Life, His Theater, His Dance.