Moving together, feeling together: Body coordination, pupil size, and musical togetherness in classical duo performance

This study investigated the relationships between bodily expression, bodily coordination, mental effort, and self-reported experiences of musical togetherness. Singer-pianist duos performed pieces of classical repertoire before and after rehearsing together. Video, head motion, respiration, and pupillometry data were collected. Afterwards, the performers watched a video of their post-rehearsal performance and made continuous ratings of how together they felt. They also provided written descriptions of the cues that informed their togetherness judgements. Our analyses showed stronger head coordination between partners and larger pupil diameter during high-togetherness phrases than during low-togetherness phrases for one of the pieces. Inhalation synchrony and quantity of head motion did not differ between high- and low-togetherness phrases. Pupil size was greater during pre-rehearsal performances than during post-rehearsal performances, suggesting that demands on attention might have reduced after players had jointly constructed a shared interpretation and grown more accustomed to performing together. A thematic analysis of written responses showed that performers’ concept of togetherness related to coherence in musical parameters, moving and breathing together, and sensations of feeling together, shared musical emotion, and effortlessness. We discuss these findings in relation to the musical togetherness model.