Jewels. The name sounds expensive and perfect for a box-office hit. But when Balanchine’s “plotless full-length ballet,” as it was touted, premiered at New York City Ballet on April 13, 1967, it had no title, only three sections called Emeralds, Rubies, and Diamonds. (Balanchine explained, “I thought of doing sapphire, too—I had Schoenberg […]