The characteristic features of ensemble dance improvisation (EDI) make it an interesting case for theories of intentional collective action. These features include the high degree of freedom enjoyed by each individual, and the lack of fixed hierarchical roles, rigid decision procedures, or detailed plans. We present a “reductive” approach to collective action, apply it to EDI, and show how the theory enriches our perspective on this practice. We show, with the help of our theory of collective action, that EDI (as typically practiced) constitutes a significant collective achievement, one that manifests an impressive, spontaneous, jointly cooperative and individually highly autonomous activity that meets demanding aesthetic standards. Its being good in this way is not a mere extrinsic feature of the artwork, but part of its aesthetic value. We end by discussing how this value is easily missed by classic aesthetics, but is revealed by more contemporary frameworks like social aesthetics.