Balanchine’s Apollo. Pictured here, Chun Wai Chan and Mira Nadon. Photo Credit: Erin Baiano October 7 matinee In its 75th anniversary season this fall, NYCB offered a matinee performance of the company’s foundational work with Balanchine’s Apollo, La Sonnambula, and Tchaikovsky Piano Concerto No. 2—allegorical, mysterious, and glorious looks, respectively, into the prolific creativity of…