In early October 1959, thirty-two-year-old Allan Kaprow presented a performance piece entitled "18 Happenings in 6 Parts." This unique conjunction of visual, aural, and physical events, performed for an intimate art world audience by his friends and colleagues, would change the course of art history. The genre of artwork that evolved from this debut would become known as Happenings. Author Mildred Glimcher, an art historian, author, and close observer...