Tonal Emergence: An agent-based model of tonal coordination

Abstract

Humans have a remarkable capacity for coordination. Our ability to interact and act jointly in groups is crucial to our success as a species. Joint Action (JA) research has often concerned itself with simplistic behaviors in highly constrained laboratory tasks.But there has been a growing interest in understanding complex coordination in more open-ended contexts. In this regard, collective music improvisation has emerged as a fascinating model domain for studying basic JA mechanisms in an unconstrained and highly sophisticated setting. A number of empirical studies have begun to elucidate coordination mechanisms underlying joint musical improvisation, but these empirical findings have yet to be cached out in a working computational model. The present work fills this gap by presenting TonalEmergence, an idealized agent-based model of improvised musical coordination. TonalEmergence models the coordination of notes played by improvisers to generate harmony (i.e., tonality), by simulating agents that stochastically generate notes biased towards maximizing harmonic consonance given their partner's previous notes. The model replicates an interesting empirical result from a previous study of professional jazz pianists: that feedback loops of mutual adaptation between interacting agents support the production of consonant harmony. The model is further explored to show how complex tonal dynamics, such as the production and dissolution of stable tonal centers, are supported by agents that are characterized by 1) a tendency to strive toward consonance, 2) stochasticity, and 3) a limited memory for previously played notes. TonalEmergence thus provides a grounded computational model to simulate and probe the coordination mechanisms underpinning one of the more remarkable feats of human cognition: collective music improvisation.

The Emergence of Specialized Roles Within Groups

“…In empirical (Setzler & Goldstone, 2020) and computational (Setzler & Goldstone, 2022) analyses of improvising jazz musicians, simultaneously interacting musicians tended to play notes that harmonically complement their partners' notes, compared to cases when one player lays down their musical track on top of a pre-existing track provided by another musician. Even if there is a prepotent tendency to synchronize actions, as some models predict, the need for complementarity in such environments may sometimes be in tension with this tendency, requiring effortful inhibition.…”

Social and nonlinear dynamics unite: Musical group synchrony

“…3) Group synchronization should be examined in human-machine interactions, research that is already advancing in pairwise comparisons [60,61]. The inclusion of one or more virtual partners in synchrony with one or more humans will permit specific interactions between subgroups to be tested.…”