Improvisation theatre (often also called improv for short) is a form of theatre in which improvisation is performed, i.e. one or more previously un-rehearsed scenes are played. The players come on stage and don't know what will happen. Usually they get a theme or a suggestion from the audience. The presenter asks, for example, about a place, a relationship, a profession, a dicey situation, a feeling, about your last visited movie. These suggestions are then the trigger and guide for the spontaneously emerging scenes. Often the players are accompanied by a musician - often also improvising.
A story develops from the spontaneity and mutual inspiration of the improv players, often far from rationality. Daily life becomes the stage. The negating intellect gives way to fantasy. "Then what is true today is true then: If I am inspired, all goes well, but if I try to do it right, there is disaster." (Keith Johnstone 1993, p. 36).
The foundations of modern improvisational theatre are the Commedia dell'Arte and the improvised comedy.
In Germany the opinion is often spread that improvisational theatre was invented by the British Keith Johnstone in the middle of the 20th century. According to his own statements, he experimented with his "Theater Machine" and created a concept called Theatersport, since the censorship in Great Britain demanded that plays be checked before they are performed. Allegedly, theatre sport could then easily be booked as a sporting event.
What is true about this story has not yet been proven or verified, as the only source that can be found is his own book, or books that refer to it.
Later Johnstone emigrated to Canada and founded the still existing "Loose Moose" theatre. In Canada there was also another form of improvised competition between two theatre teams, which is also widespread in France, Spain, Italy, etc. There is disagreement about who really started it first.
The various forms of improvisational theatre practised today can almost without exception be traced back to the student drama group "The Compass", founded in Chicago in 1955. This committed group revived the principles of the Commedia dell'Arte and - inspired by Bertolt Brecht's theatrical theories - performed socio-critical, satirical improvisations based on so-called scenarios. In addition, short scenes were improvised according to the instructions of the audience. Even before Keith Johnstone, the American viola soloist developed improvisation techniques and improv games. Her son Paul Sills developed impro in America, but the first origins of improvised playing lie much deeper in the past, in the origins of the art form of theatre itself. However, in the course of history, improvisation receded more and more into the background as a theatre tradition developed. It has been rediscovered in the meantime - similar to improvisation in music - but it has often struggled and still struggles to be recognised as an art form in its own right, the justification for which lies not only in the rehearsal work of the regular theatre business and in acting training, but also in stage practice itself.
In the mimus of ancient Greece and in the Commedia dell'Arte, improvisation played a major role. At the beginning of the 20th century there were further experiments, e.g. the Stegreiftheater, which Jakob Levy Moreno developed into psychodramatic role-playing with psychotherapeutic objectives, first in Vienna and later in the USA. However, no direct connection can be drawn to the later forms of play mentioned above, the Compass Players did not deal with the improvised theatre experiments.