The uncertainty principle in musical improvisation and interaction

This chapter considers the benefits of uncertainty for the development of improvisations and their novelty. Uncertainty is used both in a general sense, reflecting the participants’ awareness, and in the specific senses of information theory, reflecting statistical probability of an event and its separable uncertainty (indicating the degree of confidence one would justifiably have about that probability). Examples from several different musical components, such as compositional pre-structure, melody, rhythm, and pitch are discussed, alongside consideration of hyperimprovisation, metamusic, and human-controlled or autonomous machine improvisers, where performers are complemented by computational partners. Music from Louis Couperin to Miles Davis and the author’s group LYSIS is analyzed. Social interactions are discussed as a critical additional layer influencing uncertainty in improvised performance. The discussions are juxtaposed and integrated with a series of quotations from a trio of novels by Nathaniel Mackey, concerning a fictitious improvising ensemble.