Despite dire predictions that participatory musical traditions would inevitably decline in capitalist modernity in which producers are increasingly distinguished from consumers, Rio de Janeiro’s street carnival revival, on the rise in the past two decades, shows that participatory music can thrive under capitalist relations. Much of the street carnival revival celebrates the free events in the streets as forming an uncommodified, musical social movement that presents an alternative to the expensive, presentational, and commercialized samba school spectacle. Theories of musical participation (Keil, Turino) likewise depict participatory musical practices as emancipatory and oppositional to capitalist relations. The vitality of street carnival, however, depends on oficinas , or for-profit classes that teach a wide variety of Brazilian and international styles for students to play with professional teachers in participatory carnival ensembles ( blocos ). In probing teachers’ “pedagogical labor,” this article portrays oficinas as comprising a “capitalist participatory music industry.” By offering a case study on a carnival brass band community turned activist musical movement whose growth has been fueled by oficinas , I show, however, that the commodified status of oficinas does not necessarily deprive them of the capacity to build an anti-capitalist musical movement. These musicians navigate, take advantage from, and challenge capitalist realities.