improvisation [im-prov-uh-zey-shuh n, im-pruh-vuh-]
noun: the art or act of improvising, or of composing, uttering, executing, or arranging anything without previous preparation:
noun; informal: improvisation, especially as a theatrical technique.
Improvisational theatre is as old as time. It pre-dates the invention of writing, since long before we started writing scripts we were telling stories by acting them out. It has its basis in commedia dell'arte, an Italian Renaissance form of theater in which a traveling comedy troupe would perform farces without a written script. Though the basic scenario was agreed upon, the dialogue and the pacing of the story often depended on audience reactions.
After the Commedia died off, improv theatre faded into obscurity until it was separately and spontaneously re-invented by two people who have shaped the craft as it exists today -- Keith Johnstone and Viola Spolin.
Keith Johnstone and Theatresports
Keith Johnstone started formulating his theories about creativity and spontaneity while growing up in England, and later brought them into his teaching at the University of Calgary. He felt that theatre had become pretentious, which is why the average man in the street didn't even consider attending it. Johnstone wanted to bring theatre to the people who went to sporting and boxing matches, the same audience that Shakespeare had written for in his day.
Johnstone decided that one approach would be to combine elements of both theatre and sports, to form a hybrid called Theatresports. The trappings of team sports were adapted to the improvisational theatre context; teams would compete for points awarded by judges, and audiences would be encouraged to cheer for good scenes and jeer the judges ("kill the umpire!").
Through Theatresports, Johnstone's ideas have gone on to influence (directly or indirectly) almost every major improv group.
Viola Spolin and Theatre Games
Back in the 1920's and 1930's, a woman named Viola Spolin began to develop a new approach to the teaching of acting. It was based on the simple and powerful idea that children would enjoy learning the craft of acting if it were presented as a series of games.
Spolin's son, Paul Sills, built on his mother's work and was one of the driving forces of improvisational theatre centered around the University of Chicago in the mid-1950's. Along with people like Del Close and David Shepherd, Sills created an ensemble of actors who developed a kind of "modern Commedia" which would appeal to the average man in the street. As with Theatresports and the original Commedia, the goal was to create theatre that was accessible to everyone.
The group that sprang from the work of Sills, Shepherd and Close, called The Compass, was extremely successful. It brought people to the theatre who in many cases had never gone before, and eventually led to the development of a company called Second City.
Through The Compass and Second City, Spolin's Theatre Games have gone on to influence an entire generation of improvisational performers.