“Men’s ballet technique, unlike women’s, finds its expression in short bursts of extreme but controlled athleticism. … There are so many things to think about at once: the position of the feet, the torque of the turns, the composure of the upper body, the shifting gaze, the placement of the arms.” Marina Harss watches one master, Ethan Stiefel, pass on secrets to ABT up-and-comer Calvin Royal.