n research on "popular music" musicians, the analysis grid of musical genres ("rock", "jazz", "electronic music", ...) often imposes itself on sociologists with the force of evidence, even more so when - as is often the case - they are themselves music lovers. And in fact, the "genre(s)" generally constitute(s) categories of analysis of the socio-professional practices of musicians that are relatively unquestioned. Our presentation aims to show that this approach by "musical genres" masks an opposition that fundamentally structures the professional space of non-salaried musicians: that between artisan musicians playing "on demand" a pre-established repertoire in the framework of events where the production of music is secondary (a wedding ball, a supermarket animation, a socio-cultural action...) and artist musicians playing in diffusion devices where music and its creators are at the center of the attention (subsidized concert hall, art gallery...). This reflection on the relevance of "musical genres" as a category of analysis of the practices and professional positioning of musicians will lead us to a broader epistemological reflection on the impact of the position of the sociologist of the musical fact in relation to his or her object and on the consequences of the choice to position the production of music as a laborious activity. Our point is that less than the musical style it is rather the “style” of appropriation of the musical material (for instance integrating more or less the codes of the "artistic creation") and more precisely the “socio-professional style” to which it refers that seems to really determine the musical partnerships. This professional style refers less to aesthetic conventions framing the musical practice than to the "lifestyle" in the sense of P. Bourdieu, designating the material and symbolic logic shaping not only the production of musical material, but also a material and symbolic framework in which they deploy their whole life (tastes and cultural practices, outfit and bodily hexis, political opinions, consumption, ways of talking, relation to time and space, etc.). We argue that these material and symbolic economics of the lifestyle seem crucial to informs us about the structure of the occupational space, more than an approach by the musical styles.