This paper explores rhythm in social interaction by analysing how partnerdancers and audience members move together during a performance. Theanalysis draws an empirical distinction between choreographed andimprovised movements by tracking the ways participants deal with variationsin the projectability and contingencies of upcoming movements. A detailedspecification of temporal patterns and relationships between rhythms showshow different rhythms are used as interactional resources. Systematicdisruptions to their rhythmical clapping shows how audience members workwith dancers to sustain the accountability and relevance of mutualcoordination. This reveals how dancers initiate, sustain and completedistinct phases of spontaneous movement as embodied social action.