Recent studies in mobilities research highlight the ties between the circulation of cultural practices and practitioners’ mobility. On the basis of analysis of son Jarocho, music of oral tradition from Veracruz, Mexico, established in the United States and Europe, this article examines the effects of the mobility of this practice and its practitioners on the process of its definition and the boundary work by which “difference” is socially produced and organized. Studying two local scenes, in Los Angeles and Toulouse, makes it possible to examine the activities defining the practice in given contexts to reveal how such definitions count or not in how ethnicized, racialized, ethno-regionalized social groups identify themselves.