When Balanchine announced the Ravel festival, in 1975, people asked “Why Ravel?” His answer—“ Why not?”— seems to have presaged the venture’s middling success. For New York City Ballet’s “All Ravel” program in honor of the festival’s 50th anniversary, Balanchine’s Errante (formerly Tzigane) may show off the sultry Mira Nadon to splendid effect, as it did Suzanne Farrell, but it amounts to ethnic kitsch. Pavane, another Balanchine solo, involves much scarf-waving. Robbins’s In G Major is painfully thin, its jazzy score trumpeting its failure. Only Sonatine, a 12-minute pas de deux that quietly encompasses a lifetime of romance, and the macabre La Valse, with its chic mechanical Fates and an ingenue ravenous for trouble, possess staying power—and La Valse predated the festival by a quarter century. But Balanchine’s favorite-composer marathons serve another purpose than great choreography. Steeped in a single composer’s work, we begin to read the music’s mind and draw closer to Balanchine’s lifelong impossible goal: to bind his cherished music to the body, the senses, so we feel how real the intangible is. —Apollinaire Scherr