The question of what Being itself is finds its roots already in Parmenides, whose theses serve as the point of departure for Plato and, in this sense, for Aristotle and a large part of subsequent ancient Greek thought. At the foundation of this question lie two pairs of antithetical determinations: One–Many; Eternal–Temporal. When Parmenides, and after him Plato, attempt to understand Being through these essential characteristics, they encounter profound semantic ambiguities.

Already at this initial level of problematizing Being, music plays a particularly important role for the human soul and its dispositions. In the Republic, it prepares the guardians either for battle or for rest; in the Timaeus, it is responsible for the proper tuning of the human soul according to the proportions of the celestial spheres. These spheres contain within themselves the proportions closest to perfection, being the first reflection of the Eternity of the One; thus, the role of music as the bearer and transmitter of these proportions—from the heavens to the human soul—proves crucial also for the understanding of Logos itself. The fallen human being struggles to return to its perfect Being, and it turns out that, apart from reason, music too grants access to that Being.

In Plato, however, this access remains unexplained; the relation of music to eternity is abstractly clear but practically obscure. Music is presented as the art of correct proportion, yet also as the art of time, since it finds its concrete existence only during performance. How, then, do eternal proportions relate to the temporal nature of music? And why, in the Republic, is its function reduced to a merely ethical one, whereas in the later Timaeus its function acquires ontological significance—it tunes the soul according to perfect proportions?

Already against the background of classical Greek thought, the problem of musical being is discernible and possible. The greatest example is Aristoxenus, a student of Aristotle, who was the first to ground theoretical knowledge of music in hearing (and not in reason). For the first time, he places the question of Being—initiated by Parmenides—on an entirely different foundation. In this short paper, I shall attempt to articulate precisely this musical foundation: the one Aristoxenus establishes, arising from the humus of an already developed classical problematic of Being, and the one that makes the question of Musical Being possible.