Barbara Weisberger, 80, was Balanchine’s first pupil. She’s also the founder of Pennsylvania Ballet. “There are famous stories about Balanchine and his ballerina muses of course, but Ms. Weisberger, with her unusually broad perspective and tenacity, represents something more crucial in a historical sense. As a director she was Balanchine’s protégée, and she has devoted much of her professional life to teaching and promoting regional dance.”