Joint action (JA) is ubiquitous in our cognitive lives. From basketball teams to teams of surgeons, humans often coordinate with one another to achieve some common goal. Despite this ubiquity, the individual mechanisms and group-level dynamics of complex, sophisticated JA are poorly understood. We examine coordination in a paragon domain for creative joint expression: improvising jazz musicians. Coordination in jazz music is improvised and subserves an aesthetic goal: the generation of a collective musical expression comprising coherent, highly nuanced musical structure (e.g. rhythm, harmony). In this study, dyads of professional jazz pianists improvised in a "coupled", mutually adaptive condition, and an "overdubbed" condition which precluded mutual adaptation, as occurs in common studio recording practices. Using a model of musical tonality, we quantify the flow of rhythmic and harmonic information between musicians as a function of interaction condition, and show that mutually responsive dyads produce more consonant harmonies, an ability which increases throughout the course of improvised performance. These musical signatures of coordination were paralleled in the subjective experience of improvisers, who preferred coupled trials despite being blind to condition. We present these results and discuss their implications for music technology and JA research more generally.
Consideration on Adaptive Condition of Soshikokito
