Interpersonal physiological synchrony in piano ensemble performance: an interdisciplinary study of music psychology and psychophysiology

Introduction Whether autonomic nervous system (ANS)-level physiological synchrony exists between ensemble performers, and whether such coupling predicts the quality of collaborative musical performance, has not been directly examined. Methods Thirty professional piano duos ( N = 60) performed four pieces corresponding to a four-quadrant emotional design—high arousal/positive valence (HA/PV), high arousal/negative valence (HA/NV), low arousal/positive valence (LA/PV), and low arousal/negative valence (LA/NV)—based on the valence–arousal circumplex model, in a within-participants repeated-measures design. Heart rate (HR) and electrodermal activity (EDA) were recorded continuously; dyadic synchrony indices were computed via cross-correlation functions (CCF) with cross-pair surrogate permutation control. Multilevel linear models examined whether synchrony predicted expert-rated expressiveness, ensemble cohesion, and overall quality. Results Both HR-CCF and EDA-CCF significantly exceeded surrogate baselines across all conditions, with peak synchrony under HA/PV. Negative-valence conditions significantly suppressed rated expressiveness, and HR-CCF uniquely predicted ensemble cohesion, whereas EDA-CCF did not significantly predict expressiveness. Neither collaboration duration nor trait empathy reached significance, and no systematic unidirectional leader-follower structure was identified. Discussion These findings provide the first objective physiological evidence for ANS-level interpersonal physiological synchrony between co-performing musicians and offer partial support for functional differentiation between HR and EDA synchrony channels.