Miles Davis was one of the most influential jazz musicians of the 20th century because he was able to draw out of other musicians a 'sense of the possible.' He worked within an improvisational format, but had set gestures that could elicit certain threads of music such as intimacy, humor and failure. He did this by creating a ritual space that encouraged ambiguity and performing without a script. He sought the continuous present. The difficulties in analyzing improvisational work are addressed.