The focus this special issue is the microanalysis of rhythm in social interaction. When people walk together they mark together the rhythm of their walking; similarly, when people converse, their talking, gesturing, moving, and, in general, their inter-acting show rhythmic properties. We are convinced that such properties are of utmost social relevance. The four articles in this special issue are based on some of the contributions given at the panel «Rhythm in social interaction: some detailed aspects of action-in-interaction» of the 5th Ethnography and Qualitative Research Conference, held in June 2014 at the University of Bergamo, Italy. In this introduction, we shall position the special issue within the multidisciplinary field of rhythm studies, to highlight the micro-sociological, interactionist approach that we adopt here --an approach devoted to the minute, situated details of rhythmic experience, more than to cultural and/or socio-historical processes, but still focused on preeminently soci(ologic)al and interactional issues, differently than, for instance, studies in musicology or the arts. We shall then present the (multifaceted) common thread underlying all the articles --i.e., the aesthetic dimension of rhythm--, its manifold layers, and the ways in which the various contributions of this issue address them. Finally, we shall argue that the analysis of the aesthetics of rhythm in interaction allows to understand the fundamental social functions it plays, in primis as a tool for social order*. On the other hand, from a methodological point of view, we shall present rhythm as an important yet often overseen tool of the social analyst's box.