Abstract
<p>Musical ensemble coordination requires groups to stabilize shared timing while adapting to perturbations and changing rhythmic constraints. We developed an adaptive multi-frequency oscillator model of how human quartets recover coordination during switches between binary and ternary meters. The model combines nonlinear phase coupling, Hebbian-like frequency adaptation, and resonance-dependent relaxation in a four-oscillator network, allowing individual tempo adaptation while preserving subgroup-specific coupling within and between dyads. We evaluated the model against empirical quartet performances and surrogate datasets in which interpersonal coordination structure was disrupted. Parameter optimization minimized discrepancies between empirical and simulated inter-onset intervals, pairwise asynchronies, and cluster phase dynamics. Simulations reproduced transient destabilization after perturbation cues followed by recovery toward a new coordinated state. Cross-validated mixed-effects analyses showed that the model fit empirical quartets better than surrogate quartets, indicating sensitivity to genuine human coordination structure and generalization to unseen data. Optimized parameters revealed condition-specific mechanisms: within-dyad coupling was reduced in Complex–Ternary rhythms, whereas between-dyad coupling was lowest in Complex–Binary rhythms. Frequency relaxation rates were higher in Complex than Simple rhythms across meters, suggesting stronger adaptive tempo correction during polyrhythmic coordination. Stability analyses revealed bounded regions of period and phase synchronization, including Arnold tongue-like entrainment regions shaped by coupling architecture, adaptation asymmetry, and meter ratio. Together, these findings show that quartet synchronization depends on interactions among interpersonal coupling, adaptive frequency regulation, resonance-dependent constraints, and rhythmic ratio constraints. The model provides an interpretable dynamical framework for understanding how human groups recover, maintain, and reorganize coordinated behavior under changing rhythmic demands.</p>