More than any other art, classical ballet makes gender its problem. The focus is obvious but subtle. Almost every class is two-thirds female and the hallways of a ballet school are always disproportionately pink. But ballet also curates a vision of femininity as the very ideal of its practice. The vision is manifest not only in the old, narrative productions of the nineteenth century—like The Nutcracker, or Swan Lake, or Giselle—full of the tiaras and…