This article is a study of the musicians who laid claim to the aesthetics of free jazz in France and a contribution to the analysis of the phenomena of overarching radicalism. While the assignment to radicalism of this musical movement by its French commentators was at first the result of a complex and delayed transfer and the reception of a musical form that appeared in the United States, it also echoed the political commitment of musicians in the context of the French “May” and the disengagement linked to the ebbing activism of the 70s. Based on testimonies and the study of the music and militant press of the time, this article attempts to reconstruct a dynamic of radicalization that is both original and partially obliterated.