There may be an exercise during a dance class or indeed an entire class dedicated to movement improvisation. Here are some ways that I approach music for this environment.
Possibly, whoever is leading the improvisation may give a specific musical direction for the music.
Quite often, the dancers are given a brief form of direction and the musician is then asked to `play when ready`. My first response in this case, is to wait and envelope the ambience of the room listening to the general environment for sounds. It is a very rare occasion that you will ever find silence (don`t think I ever have). I usually begin to play quietly and attempt to blend with the environmental sound scape attempting not to affect any one particular person in the space. Whatever the instrumentation, I am looking to create as varied a timbre as possible.
I may react and make a dialogue with any one of the environmental sounds and have found that this opens the ears and encourages sensitivity, inspiring fellow protagonists to create their movement from yet another dimension.
This clip shows Michael Schumacher in the process of developing a student choreography, a fantastic performer, choreographer and teacher of Improvisation.
To be continued.