New York City Ballet opened its winter repertory season on Tuesday night, closing the program in timehonored fashion with a performance of Balanchine’s “Symphony in C.” Watching Wendy Whelan and Philip Neal in the adagio, I thought again about what distinguishes the great Balanchine adagios from their 19thcentury predecessors.Though many of the steps are the same, Balanchine not only phrased them differently but morphed the adagio language so that even when there was a visible derivation for his vocabulary, he offered steps, lines, and images one doesn’t quite recall seeing in any other choreographer’s canon.

Just as essential in Balanchine’s revision of the classical adagio was his determination to excise emotional incidents and plot lines while retaining the emotional potency, the inherent poetry in adagio vocabulary. “Symphony in C” can stir an audience profoundly with movement that symbolizes human aspirations to transcendence, and Ms. Whelan’s performance Tuesday night was an exemplary interpretation of what Balanchine wanted.

Without explicit emoting between the man and woman, the “Symphony in C” adagio nevertheless is suffused in an emotional haze – dreamy, romantic, otherworldly – that seemed to envelop Ms. Whelan. She worked her sinews and tendons at all times to suggest incorporeality. She raised her leg to her opposite knee in a slow, contemplative passe, and put her leg languidly down to the ground when she descended from the first sequence of slow supported lifts opening into arabesque.

The “Symphony in C” adagio has been danced beautifully by smaller ballerinas like Allegra Kent, but it works best on a tall, very thin dancer like Ms. Whelan. Her lines were well nigh flawless, and she made spectacular the diagonal in which, supported by Mr. Neal, a huge swing of her long legs propelled her body into an about-face. She even made graceful one of the slightly awkward moments in the adagio, a shuffling bourree on half toe that precedes the repeat of the arabesque lifts that she and her partner performed at the beginning.

Ms. Whelan celebrates her 20th anniversary with NYCB this year. Not only dancing an encyclopedic repertory, she also has managed to make clear stylistic discriminations between ballets, rather than letting her workload dissolve into a blur. There have been times in her career, however, when she was forced to be a Jill-of-all-trades, prevented from completely realizing herself in any one role because her repertory was so exhaustive.

For years Ms. Whelan has carried on even when some of her similarly indispensable colleagues have succumbed to injuries. The onus of carrying the company has taken less of a physical toll than would seem possible, but a year ago Ms. Whelan herself returned from a major injury. Her jump is now lower, and she was slightly tuckered out in the allegro fireworks of the “Symphony in C” finale, but virtually no ballerina who has brought her adagio technique to the level Ms. Whelan demonstrated Tuesday night will be quite as proficient in allegro. She was steadier in the allegro finale of “Symphony in C” than she was a year ago in the equivalent conclusion to Balanchine’s “Diamonds.”

As a whole, NYCB rose to the season-opening occasion. The measure of Mr. Neal’s success is that for long stretches of the adagio I was hardly aware of him, merely conscious that a solid cushion of support was allowing Ms. Whelan to move transparently through all the difficult evolutions of the adagio. In the finale, he performed sterling pirouettes.

In the first movement of “Symphony in C,” Jenifer Ringer replaced Jennie Somogyi, who had replaced Miranda Weese in the performance of “Fearful Symmetries” that preceded “Symphony in C.” Implanted in Ms. Ringer’s brain and muscular reflexes was a per fect understanding of the role, but she wasn’t quite in the physical shape needed to fulfill her blueprint. Her partner, Nilas Martins, just coped with the steps, but delivered some good pirouettes of his own in the finale.

In the third movement, Benjamin Millepied was almost unrecognizable. He was much more energized than I’ve seen him over the past couple of years; rather than pinched and brittle, he was buoyant and expansive. Although Megan Fairchild didn’t demonstrate an enormous jump to match his, she was fine technically. She needed to sell herself a bit less aggressively, however, and toning down her presentation would make her persona here more than cute – potentially, she could be glamorous.

Abi Stafford and Jonathan Fowler were also impressive as the soloist couple of the fourth movement.Theirs are the shortest among the lead roles, but perhaps the most technically difficult, packed with steps and directional shifts performed to the speediest of passages in a ballet that, except for the adagio, is nearly all festive effervescence. Ms. Stafford did not make her last pirouette in the diagonal sequence a double, the way some dancers do, but that was probably due to the vagaries of the moment: The added fillip is undoubtedly a part of her technical arsenal.

City Ballet’s winter season runs until February 26 at the New York State Theater (Lincoln Center, 212-870-5570).