Within the framework of the theme Music–Power, our aim will be of showing that, in the opposition between passion and reason, love and duty, free will and destiny, it is the problematic of sublimation that is at stake. We will first sketch, from a theoretical viewpoint and in the perspective of Freud and Lacan, the stakes of sublimation; we will determine that it belongs to its nature to be in the service of the Law, in the widest sense of the term. Thereafter, we will propose a distinction between ethic and aesthetic sublimation. We will argue that the exception of the work does not reside in its message, but rather it the singularity of its being put into work. We will discuss as an example the case of the only true opera by Purcell, Dido and Aeneas. We will shew that beyond the apparent message of this episode from the Aeneide, a signification can be perceived, proper to Purcell’s own reading, the effect of which arises exclusively through the composer’s elaboration of the musical material. We will analyze one aspect of this elaboration, the tonal construction. It is in this way that the proper speech of the artist always expresses itself through artistic activity, beyond the Law to which it seems subjected.