Math{\'e}matiques, musique et cosmologie : A partir du Tim{\'e}e de Platon

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 poétique, 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. AMS classification : 00A65, 00A30, 97M80, 01A20, 97A30