Structural Regularities of Extant Improvisations Reveal Cognitive Constraints and Motor Associations

Extant improvisations serve as a record of a creative act originally conceived under real-time constraints. Classic work by Pressing predicted that improvisations would contain a series of concatenated musical gestures or patterns. Indeed, analyses of both corpora of improvisations from individuals and groups of jazz improvisers show strong evidence of repeated patterns. Looking further at structural regularities, a phenomenon seen in language where easier words appear at the beginning of sentences also applies to improvisations. Indeed, musical phrases in a collection of 456 iconic jazz improvisations begin with more frequent and less complex sequences, allowing incremental planning later in the same phrase. Pressing also predicted that individual improvisers would develop a vocabulary of musical patterns linked to associated motor movements. Improvisations by one artist-level jazz pianist were compared with a control corpus consisting of improvisations by 24 different advanced pianists. Though both corpora contained many recurring patterns, the single-player corpus showed stronger links between pitch patterns and motor programs. Finally, network science is used to model how patterns within an improvised corpus are organized. Future research is suggested to further explore processes by which patterns in musical improvisations are selected and concatenated.