Watching the New York City Ballet in action has the force of revelation on almost every occasion, but all the more so when you haven't seen it in a while.

The troupe returned to the Kennedy Center Opera House Wednesday night for the first time since the fall of 1985, bringing the point home once more. This is what excellence in classical ballet looks like and feels like. This is the top.

To be sure, there are other great ballet companies in the world, both in this country and abroad. We've seen a magnificent parade of them pass through Washington since NYCB was last here, each with its own treasurable artistic identity and particular strengths. But when all is said and done, NYCB comes closest to the ideal that a modern imagination is apt to hold dear -- a union of perfected form and substance pared of everything extraneous, and synchronized with our quickened contemporary pulse.

The program that opened the company's two-week engagement spotlighted three major veins of its repertory -- George Balanchine's drastically streamlined version of "Swan Lake" in a startling new physical production; "Agon," perhaps the quintessential Balanchine-Stravinsky ballet, dating from 1957; and "Brahms/Handel," a 1984 collaboration between a Jerome Robbins and modern dance iconoclast Twyla Tharp exemplifying the continuing exploratory thrust of the company's post-Balanchine era.

"Swan Lake" led things off. Balanchine's one-act, 1951 version of the Tchaikovsky classic compressed the traditional Acts 2 and 4, distilled the plot, eradicated all but the merest vestiges of mime, speeded the dancing to electric velocity and yet retained withal the tragic poignancy at the heart of the original.

Last year's new production has startlingly unconventional de'cor and costumes by French-born artist Alain Vaes. The set is an ice cavern, its jagged foreground stalactites framing a lakeside panorama with Gothic towers and massive glacial peaks in the background. The whole concept inverts the usual "Swan Lake," where the background is generally dark and the dancers are in white. Vaes makes the surroundings predominantly white, and puts the swans in black tutus except for Odette, Queen of the Swans, still costumed in white.

On the whole, the color scheme and the imagery enhance Balanchine's stringently abstract "Swan Lake." The ice and the black swans together reinforce the severity of Balanchine's conception, and the visual accent on Odette is no less fitting. The story of the traditional, full-length "Swan Lake" revolves around Siegfried, the Prince, but for Balanchine -- ever inclined to put women at the center of things -- it's a ballet about Odette as an icon of doomed love. Vaes' gargoylish costume for Von Rothbart lends newly sinister overtones to the role of the evildoer.

Substituted for injured Merrill Ashley, Darci Kistler gave us an Odette that was one long transport of exquisitely controlled passion. It was seven years ago nearly to the day that Kistler, at 16, danced her first Odette with NYCB here at Kennedy Center, disclosing the precocious intensity that made Balanchine single her out, the last dancer to be thus privileged. The royal radiance of her Titania in "A Midsummer Night's Dream" during the company's last visit still pulsates in memory. She couldn't seem to find a comfortable tempo for Odette's solo variation Wednesday night, but otherwise her dancing was flawless. Her Siegfried, Adam Lu ders, was stirringly brooding and troubled -- he's touching precisely because he's so odd in the role; a fragile Siegfried. The demi-soloists and the ensemble were so fast and machinelike that this became a New World "Swan Lake" with a vengeance, yet Kistler's lofty pathos kept reinstating the Tchaikovskian soul.

To go from "Swan Lake" to "Agon" is to leap from a bygone world of myth and rapture, however modernized, to the cerebral gymnastics of the electronic age. "Agon" is classic in its austere economy of means, in its cool surfaces and surgical clarity of form; it is contemporary, even futuristic, in its calculated eccentricities of shape and rhythm, its spaced-out textures and dry wit. Balanchine's choreography proceeds like a mathematical demonstration, moving step by chiseled step in an inexorable progression. Small units recombine in fractal layers to form ever more intricate wholes; at the apex is the absurdly quirky, atomic circus act that is the work's single piercing male-female duet, danced on this occasion with almost nonchalant yet burning mastery by Heather Watts and Mel Tomlinson. The other principals of the exemplary cast were Lourdes Lopez, Jock Soto, Helene Alexopoulos, Victor Castelli, Lauren Hauser and David Otto.

"Brahms/Handel" is a tour de force of an abstract ballet that is its own spoof at the same time, a sort of Super Bowl -- the dancers are divided into two "teams" of 14, one in blue, one in green -- of choreographic teasers. It doesn't show off either Robbins or Tharp at their creative best, probably for the very reason that each is deferring to the other. But what it does have is a good-natured combination of rivalry and camaraderie that couldn't have happened except by means of partnership. The two seem to be trying to outdo one another in craftsmanship, surprise and athletic kookiness. At the same time, they so disguise their stylistic signatures that the ballet is like a two-men-in-a-horse act -- you really can't tell with any assurance who did what, choreographically.

The music -- Brahms' "Variations and Fugue on a Theme by Handel," as orchestrated by British composer Edmund Rubbra -- is the same kind of anomaly as the score for "Les Sylphides," that is, thoroughly idiomatic piano music wrenched from its natural sonic ground. And Oscar de la Renta's all too designerish costumes don't suit either composer well. Just the same, the dancers, led lustily Wednesday night by Kyra Nichols, Robert LaFosse, Maria Calegari and Jock Soto, throw themselves into the enterprise with persuasive gusto.