The article proposes to sketch an analogy between, on the one hand, linguistic learning and sound dialogue in humanist music therapy and, on the other hand, certain reflections of Maurice Merleau-Ponty: in particular, the centrality of corporeality in the learning, treated in the Phenomenology of Perception and in the courses on the psychology and pedagogy of the child, and the status of inter-corporeality developed through reflections on passivity and the metaphor of flesh. We will trace an analysis of the music therapy of Giulia Cremaschi Trovesi, with reference to the linguistic and musical gesture, through the Merleau-Pontian notion of praktognosia, and of the sound dialogue with reference to institution and intercorporeity. Through an interpretation of music in the terms adopted by Stéphanie Ménasé and in reference to Merleau-Pontian passivity in artistic creation, our objective is to define the musical institution of the vibrating body in music therapy in terms analogous to the institution of the subject according to Merleau-Ponty and, consequently, to find, in the sound dialogue, the intercorporeity which anticipates the individuation of the subject, by describing the communicative authenticity of the musical-therapeutic encounter.