New York City Ballet’s spring season is six weeks long and the first two weeks brim with Balanchine. On April 20, Concerto Barocco sees the debuts of Sara Mearns and Isabella LaFreniere in its two lead roles, and debuting on the evening of April 22 in Kammermusik No. 2 are the glamazons Emily Kitka and Miriam Miller. There’s also Raymonda Variations, Square Dance, Haiff Divertimento, and Donizetti Variations. Jerome Robbins’s breathtaking Afternoon of a Faun, in which Mallarmé’s dreamy meeting between two young creatures is updated to an empty rehearsal studio, is the only non-Balanchine work to slip into this rep. On April 23, the corps dancer Dominika Afanasenkov debuts as the young dancer lost in thought. —Laura Jacobs