Generally, happening refers to the taking place or occurrence of an event or incident. In the context of art, a happening refers to a category of performance art which was popular in 1950s and 1960s. Happening was a combination of music, poetry, painting, dance and drama. The term happening was first used by American artist Allan Kaprow in 1957. The theatrical pieces had an element of unexpectedness. The viewer was an integral part of the happening and therefore each presentation was different from the other based on the reaction of the audience.