Treatise on Universal Harmony

that pertains to Optics, Catoptrics, and Dioptrics.

The Fourth explains what pertains to the bodies that make sound, and shows what proportion there is of the density, rarity, length, and depth of bodies with sounds; teaches several other things that have never been treated, and the rarest secrets of Mechanics; and shows how one knows the nature of each body by the sound it makes.

The Fifth explains the Consonances, their reasons, powers, and properties, and the manner in which one can use them in all sorts of compositions; and gives the reason for all the passages that are made from one Consonance to another, and why one passage is better than another.

The Sixth explains the Dissonances, their reasons, their properties, and the use that they have in Music.

The Seventh declares what pertains to the voice, to its organs, and to songs; determines if one can judge the nature and temperament of men and animals by their voices; shows what relationship there is of the tongue and of speech to hearing and its organs, which are explained in the same book, and gives the use and the Theory of Accented Music.

The Eighth treats the Genres of Music;