The week-long run of George Balanchine's "A Midsummer Night's Dream" at the Kennedy Center Opera House gave the New York City Ballet a chance to flex its muscle to a degree unusual even for the nation's largest (100 strong) dance company. All of the ballet's 14 highlighted roles were either double- or triple-cast, including the five major dancing (as opposed to mime or character) parts -- Titania, Oberon, Puck and the Divertissement couple -- without nearly exhausting the company's potential for filling them. Balanchine's choreography, Mendelssohn's music and Shakespeare's story and characters assured a constant level of artistic reward, but every performance brought new shadings and inflections, illuminating the richly faceted work from a different angle each time.

On Friday night and Saturday afternoon, with a pair of new Titanias, the whole became first less and then more than the sum of its parts. Pretty, delicate and fine-boned Maria Calegari is a lovely dancer of somewhat elusive personality, whose Titania Friday night was neatly danced, apart from overly florid arms, but pallid in characterization, not quite a sovereign of the fairy kingdom. She was at her best in the duet with Bottom (Kipling Houston), where her lyricism could overcome the missing regality.

On the whole, Friday, the balance between broad humor and romantic fantasy tipped too much toward the former -- it's important for Bottom and the mortal lovers to remember that it's their plight that is comical, not the characters themselves. Among the redeeming graces of the performance was the dancing of Patricia McBride and Joseph Duell, stepping in for the first time as the Divertissement couple. McBride's beautifully understated legato in the adagio responded to the euphoric side of the music; Duell's unfailingly noble line lent McBride just the unaffected support she required.

Saturday afternoon's Titania -- blond, tall and willowy Nina Fedorova, who looks as if she were designed by Erte -- was also more picturesque than effulgent, but her height and the sweep of her movement gave her a sufficiently queenly aspect. With Lauren Hauser as a very appealing new Hermia and Houston as her Lysander, the quartet of mortal lovers was the most persuasive one since the start of the run. Douglas Hay's affectingly shy Bottom and Teresa Reyes' bold Hippolyta also added perceptibly to the dramatic impact of Act 1. Kyra Nichols danced far more pointedly and eloquently her second time around in the Divertissement duet, with Adam Luders showing a gain in confidence as her partner. The orchestral performance, under the baton of Hugo Fiorato, was also more polished than it had been Friday evening.

Looking back, last Tuesday's opening-night performance still seems unmatched in form and emotional resonance, climaxed as it was by Darci Kistler's celestial Titania, Ib Andersen's brilliantly authoritative Oberon and the poignancy of Heather Watts in the Divertissement. Even so, the multiple casts were a delight to observe, reaffirming both the company's resilience and the ballet's enduring spell. A last bravo, too, for the precision and spirit of the participating Washington area children, who played no small part in conjuring the magic.