  Based on Plato's Timaeus, we present some reflections on music, cosmology and
mathematics and their mutual influence.The article is dedicated to the composer
Walter Zimmermann. The final version of this article will appear in the volume
"Les jeux subtils de la po{\'e}tique, des nombres et de la philosophie. Autour
de la musique de Walter Zimmermann", ed. P. Michel, M. Andreatta and J.-L.
Besada, Hermann, Paris, 2021.
