The New York City Ballet returned to the Kennedy Center Opera House last night after a season's absence for the start of a two-week engagement. In a way, that says it all.

While they're gone from us, we think we know how fervently we crave their presence. The truth is, though, that imagination isn't equal to the job of conjuring up this degree of excellence. We don't really know how much we miss them till they're back, and the living reality of it hits us once again in the breadbasket.

Let's face it, this company is so good it hurts. Of course there are other great ballet companies, in this land and abroad. But there's only one New York City Ballet. Other outfits consider themselves lucky to have a handful of virtuosos of the first rank -- this troupe is overflowing with them. Some are more experienced, some less; some are distinguished artists, some are fledglings. But there are no peasants here, only nobles. Then there's the repertory, with its unparalleled treasury of Balanchine works at the core. This is also the most contemporary of all ballet troupes. The few 19th-century ballets in stock have been chromed into unmistakable modernity. And the spirit of the NYCB puts one in mind of great feats of engineering in its home city -- the Brooklyn Bridge, Radio City, the Chrysler Building. It shoots up strong and skyward, grabbing for the future.

The performances on this first night seemed somewhat subdued, as this company goes -- that is, until "Symphony in Three Movements," the juggernaut of a Balanchine ballet that closed the program, each work of which was set to music by Stravinsky.

The impression of understatement was felt from the opening "Apollo," beginning with the orchestral prelude, which conductor Robert Irving took at an unusually attentuated pace, emphasizing more the lyric plangency of the score than its rhythmic ribs. On the whole it was an "Apollonian" performance, in the sense of pristine clarity and composure. The cast, certainly, could not have been closer to ideal -- Ib Andersen as a friskily assertive Apollo, almost more like a Pan, and as his three Muses, Suzanne Farrell, Kyra Nichols and Maria Calegari. They all danced like the thoroughbreds they are, yet without the blinding intensity this ballet is capable of summoning. Somehow, the dancers were upstaged by the timeless majesty of the choreography, and by the ways in which this ballet -- the earliest (1928) Balanchine in company repertory -- adumbrates so much of what followed in the master's later career.

Next came Jerome Robbins' "Concertino," set to a couple of particularly astringent Stravinsky chamber works. It won its cast -- Merrill Ashley, Sean Lavery and Mel Tomlinson -- a well-deserved triple curtain call, even though these superb dancers also seemed a jot less keyed up to the crisp wit of the piece than they might have been. It's a ballet that shows, in its jaunty dislocations of the classical vocabulary, how deeply even Robbins is indebted to Balanchine, though there's much in the streetwise raffishness of the work's energy that speaks distinctly of its author.

Patricia McBride, Bart Cook and Jerri Kumery were the expert principals in Balanchine's "Capriccio for Piano and Orchestra" (actually the "Rubies" movement of the full-length "Jewels" ballet). Here again, one would characterize it as a sparkling but not quite electric performance, despite the aptly casual impudence of the soloists and the brisk, incisive edge to the dancing by the ensemble of 12.

There was enough electricity in the "Symphony in Three Movements," however, to make up tenfold for any diminished voltage in the rest of the evening. The gasp that went up from the house at the opening display of a perfectly aligned diagonal of 16 women in white, all sporting ponytails, was a natural response to a dazzling tension that built to peak upon peak from that moment on. The ballet is one that Balanchine himself never surpassed, a large structure of awesome speed and complexity that mysteriously fuses bristling athletic exuberance with an undertone of almost militaristic menace. It's all devastatingly summed up in the unforgettable final image, with the eight men in a taut, low crouch, ready to spring to the attack, so to speak, and the women standing in a grid with arms stretched vertically and horizontally, weirdly suggesting at once a field of goal posts and a barbed wire fence. Victoria Hall, Melinda Roy, Heather Watts, Jean-Pierre Frohlich, Kipling Houston and Jock Soto were the scintillating principals, splendidly abetted by five demi-soloist couples and the female ensemble. Watts' agonized ecstasy in the Eastern-tinged middle movement (with Soto as her partner) was especially memorable.