RECENTLY, MISSING THE BALLET PERFORMANCES I’d planned to attend this spring, I revisited a short video-installation piece I love: En Puntas by Javier Pérez, featuring a ballerina with long knives strapped to the soles of her pointe shoes. It was filmed in the Teatre Municipal de Girona, in Spain, in 2013. The dancer, Amélie Ségarra, sits on the lid of a baby grand piano, tying the pink shoe-ribbons around her ankles. With the help of a rope dangling from the ceiling, she hoists herself up until she’s balanced on the sharp tips of the knives, her feet hovering eight inches