The heaven of Mars may be compared to music because of two properties: one is its most beautiful relation, for in counting the moving heavens [...] [it is] the middlemost of them all [...]

The other, as Ptolemy says in the Quadripartitus, is that Mars dries things out and incinerates them because its heat is like that of fire [...]

And these two properties are found in Music, which consists entirely of relations, as we see in harmonized words and in songs, whose harmony is so much the sweeter the more the relation is beautiful [...] Moreover, Music attracts to itself the human spirits, which are, as it were, principally vapors of the heart ...

Convivio II, XIII, 20-24