My research revolves around the bodily expression of emotion and the study of non-verbal communication in groups. I consider music ensemble performance as a test-case as it provides a large range of expertises (from absolute beginner to renown expert) and force the research to deal with situation of interaction that offer various levels of complexity : from rather basic alignement (moving altogether at the same pace) or highly complex (consider the fine-tune movement and shift coordination of violinists in a string quartet).