Drawing on a half century of documenting performance across multiple genres, from post-modern dance to physical theater to body work, as well as site-specific performance, with audiovisual examples from some 53 practitioners, including Eugenio Barba, Tim Etchells, Joan Skinner, Kristin Linklater, and Steve Paxton, Peter Hulton’s “A Digital Essay on Performance”considers performance as a body in operation with imagery and attempts to identify some of its foundational features.