The Brief Treatise on Ratios That Pertain to Music (1409) is a concise summary of the traditional doctrine of ratios. In A Little Treatise on the Method of Dividing the Monochord (1413) Prosdocimo established, for the first time in Italy, a complete Pythagorean monochord, dividing the octave into seven natural notes, five flats, and five sharps not enharmonically equivalent to the flats.
