The exceptions to this general trend are Sara Mearns, Tiler Peck, and Sterling Hyltin, who continue to hold pride of place in the repertory and onstage. Mearns is dancing with, if possible, even greater authority, tinged with a new quality, almost a slight detachment, the serenity of an artist at the peak of her powers, dancing mainly for her own pleasure. It is an intriguing shift for this dancer, who has always shown such hunger for the stage. Hyltin, sometimes relegated to less than ideal partners—no-one has ever replaced Robert Fairchild, with whom she had a great partnership—found new joy dancing alongside Mejía in “Rubies.” And Tiler Peck finally took on some of the roles that have eluded her so far.

One of those, on the evening of February 5, was that of the ballerina in Balanchine’s late work “Mozartiana,” made for Suzanne Farrell, and set to Tchaikovsky’s orchestrations of four Mozart pieces. It’s a role usually given to taller, grander dancers in the Farrell mold, not necessarily Peck’s natural habitat. It is fascinating to watch this highly intelligent dancer apply her musically sensitive and technically assured approach, first to the quiet preghiera, and then to the witty theme and variations. In the first, she toned down her tendency to overlay the steps with her own theatrical interpretation, allowing the slow, simple movements to speak for themselves. In the second, she played with timings—her specialty—finessing and coloring transitions. The result was a well-thought out and honed “Mozartiana,” but one that was slightly lacking in naturalness and the sense of a long arc from start to finish. Instead, as she often does, she held up a magnifying glass to individual moments. (This was her approach in “Rubies,” in which she débuted earlier in the week, but there, it became obtrusive, as if she didn’t trust the choreography to convey sufficient humor on its own. It was the first time I’ve seen Peck look slightly insecure in a role.)

The Saturday evening performance of “Mozartiana” was also a début for Harrison Ball, a promising soloist who had previously danced the gigue with great style. He looked rather tense, but danced elegantly and lightly, his feet fluttering beneath him, executing clean turns, and generally making his way through the gauntlet of steps with distinction. Perhaps once he relaxes a bit, the ballet will acquire that air of civilized banter that made Sara Mearns’s performance alongside Russell Janzen, earlier in the week, such a delight.

Mearns and Janzen paired up once again at the Saturday matinee in Balanchine’s windswept “Walpurgisnacht Ballet,” set to the ballet music from Gounod’s Faust. We haven’t seen much of Janzen lately, and his return has been welcome. He is one of the tallest men in the company, a dancer with an unforced, easy-going elegance, affable stage presence, and seemingly effortless partnering skills. And he and Mearns have a wonderfully warm, communicative stage relationship; they look at each other squarely in the face, communicating with their eyes. And he seems to anticipate her needs, offering his hand at just the right moment to assist her out of a turn, or release her in a balance.

Mearns has long dominated the role of the ballerina in “Walpurgisnacht,” approaching the steps with a kind of nonchalant grandeur (even more nonchalant at this performance), whether walking slowly on point, lifting one leg high and then bringing it in slowly in an enveloppé, or executing a diagonal of coupé turns. This was Janzen’s début; a couple of the landings from jumps didn’t go as planned, but the role, which consists mainly of partnering, suits him well.

Casting is a delicate and complicated art, one that sometimes brings surprising results. Who would have thought, for example, that Ashley Laracey, a quietly poetic dancer, would be so convincing in Merce Cunningham’s “Summerspace,” performed earlier in the season? On Saturday afternoon, she had her début in Balanchine’s “The Unanswered Question,” from the 1954 ballet “Ivesiana” (set to music by Charles Ives). She was haunting as the angelic/totemic/ghostly figure who glides and somersaults through the air (manipulated by four men in black, like puppeteers), hovering inches from a man who reaches desperately for her in the darkness. One of Laracey’s most powerful qualities is her ability to convey vulnerability. As you watched her here, you sensed the character’s emotional fragility; she may have been a ghost, but she was a ghost with a troubled heart. Harrison Coll, also débuting, convincingly embodied the man’s anguish, his overpowering desire to reach the figure who stays just beyond his grasp.

Unsurprisingly, the soloist Roman Mejía, a virtuoso with a sly smile and confidence to burn, was a showstopper in “Rubies” at his début on Saturday evening. It looked as if he had been waiting his whole life to dance the role, with its high-flying, galloping, throwaway feel. (The role was débuted by Edward Villella, another charming allegro dancer.) Mejía takes clear pleasure in partnering; he makes it look fun, which, in turn, made his partner, Sterling Hyltin, look like she was having the time of her life. The whole performance was a romp, with Mira Nadon blazing in the role of the soloist who vamps, kicking her long legs, tipping her shoulders, brazenly flirting with the four men who attempt to partner her. How did Nadon gain so much confidence so quickly?

There were yet more débuts, in Balanchine’s 1951 “La Valse,” a nightmare ballet that sets in motion a poisonous whirlwind of vanity and falseness. Early in the week, Taylor Stanley brought his delicacy and attention to detail to the ballet’s final tableau, in which an ingenue, in white, is torn between a well-mannered partner (Stanley) and a figure of death. (Death wins.) Of particular note was the way Stanley used his hands, sheathed in white gloves, as if expressing flattering phrases with his fingertips. On Saturday evening, the ingenue was played by Indiana Woodward, newly promoted to principal. It is the first time I have seen her in a serious role, and she threw herself into it, her stylish dancing quickly churning into giddy abandon.

On Saturday afternoon, Jerome Robbins’s 1959 ballet “Moves,” performed in silence, returned after an absence of several years. It’s a “thinking” ballet, in which Robbins broke down aspects of ballet technique, deconstructing the relation of movement to time and dynamics of partnering. Men partner men, women partner women, partners replace each other mid-phrase, and dancers mimic partnering while dancing on their own. Hidden cues keep the rhythm of the movements in sync. But the ballet is also a compendium of Robbins-isms: dancers running, reaching, folding, splaying their fingers. The result is clever, a little stilted, and over-long. In the cast were many of the company’s rising soloists and notable members of the corps: Emilie Gerrity, limpid and strong; Harrison Coll, down-to-earth and all-American; Christopher Grant, ebullient and present.

It is an interesting time to be a City Ballet observer, watching the tide turn, as seasoned dancers discover new vistas, or move beyond the horizon, clearing the space for a new wave.