Multiscale synchronisation dynamics reveals the impact of an improvisatory approach to performance on music experience.

Experiences of collective creative activities play an essential role in human societies, yet these experiences are particularly hard to capture, making their scientific study challenging. In a classical music concert-experiment performed by a string quartet, we contrast a Let-go performance mode, characterised by a more creative and improvisatory approach that encourages risk-taking and spontaneous expression, with a more Strict mode which requires adhering closely to the score, common in many Western classical music performance environments. We investigate the experience of audience members by analysing their subjective reports and movement patterns. Our results show that during performances in Let-go mode, movement synchronization was reduced between performers and audience members in shorter timescales, while the synchronization and its temporal variability were enhanced in longer timescales. Furthermore, these differences in the synchronization dynamics are predictive of changes in the audience's perception of music. These results provide a first step towards the quantification of some of the fundamental aspects of collective music experiences. Specifically, the reported findings demonstrate the relevance of the often-neglected multiscale coordination between audiences and performers, and explain how this rich tapestry of physical behaviour is connected with the quality of the collective music experience.