How could be evaluated the contents that an articulated musical structure contains and expression? In a first moment, the answer causes a “scrolling” in at least three models of representation distributed between the composer, the performer and the audience. But all three performers are part of a larger whole that is society. But this, in turn, “defoliates” into three entities that define its evolutionary dynamics: the past (history), the present (the realization of inherited values and the formulation of one's own values) and the future (perspective goals), after which follow the historical types of organizing large human groups, each with its own imagination, values and goals. Next come the institutions specialized in the formulation and maintenance of musical life, but also in the conservation of representative works and names as a canon. And some (the composer and the performer) and the others (the public) will exist in a specific, temporal-historical and spatial-geographical pool of the collective imaginary, which will first of all define what is the social command, with which willy-nilly the musician will comply, but will also try to reformulate its contents. And in the European space, one with an intensely evolutionary history, there will be ceaseless grateful battles for the adjustment of music to the new consensual states of the collective consciousness. And every time, the music will represent a faithful emulation as content of the convergence of all actants, states and conjunctures, evolving together with them and thus advancing towards a new and new music every time. In the end, the sacramental question What is music? he will not find an answer other than a partial one. An honest answer, formulated exactly in the spirit of Bach's obedience, in the word übung, which means exercise. In the mysterious questions of Pascal Bentoiu. As well as in the text of this study.