What is it that characterizes a conservatory ? What music does it teach, and how? Far from being a mere music school, based on the model of the National Conservatoire of music founded in France in 1795, the institution obeys a particular conception of music and of musical practices. The Conservatoire indeed relies on Jacobine ideals. Opposing against ecclesiastic and foreign control of music, it must be a laique and national teaching institution, able to produce on the new musical market entirely French productions, from the formation of the musicians to the musical performances. The institution also is characterized by the framing of the outer and inner space. The framing of the outer space passes through the centralized network of provincial conservatoires, conceived as dependent from the Paris Conservatoire. The framing of the inner space passes through the closure of the Conservatoire and the spatial individuation of the students according to their progress, their specialty and their class. Space for living, the Conservatoire also becomes a disciplinary space as defined by Michel Foucault. The control of the manners and the sexuality of the students results in repeated musical rehearsals in the classroom. Abstinence and rehearsal are supposed to determine a virtuous circle, aiming at the conservation of music: chastity leads to more frequent rehearsals, and music helms remaining chaste, in a circular movement that allows maintaining the repertoire. The Conservatoire therefore is a specific music school, above either criticism or praise. It is not certain that such a model, imagined in a specific context, is fitting for the teaching of a novel music or of novel ways of performing it.