Expressive Non-verbal Interaction in String Quartet

The present study investigates expressive non-verbal interaction in musical context starting from behavioral features extracted at individual and group level. We define four features related to head movement and direction that may help gaining insight on the expressivity and cohesion of the performance. Our preliminary findings obtained from the analysis of a string quartet recorded in ecological settings show that these features may help in distinguishing between two types of performance: (a) a concert-like condition where all musicians aim at performing at best, (b) a perturbed one where the 1st violinist devises alternative interpretations of the music score without discussing them with the other musicians.