The central set of "harmonies" was the musica universalis or "music of the spheres", which had been studied by Pythagoras, Ptolemy and many others before Kepler; in fact, soon after publishing Harmonices Mundi, Kepler was embroiled in a priority dispute with Robert Fludd, who had recently published his own harmonic theory.
Det centrale sæt af "harmonier" var musica universalis eller "sfærernes musik", som var blevet studeret af Pythagoras, Ptolemæus og mange andre før Kepler; faktisk blev Kepler selv, kort efter udgivelsen af Harmonices Mundi, indblandet i en strid med Robert Fludd, som også lige havde udgivet sin harmoniske teori, om hvem der havde fortrinsret.