Chapter 7 will examine the question of consonance and dissonance of musical ratios and intervals in the medieval Islamic world and the growing importance of the human soul in the discussions pertaining to this question. The Pythagoreans, having conceptualized the relationship between two notes as a numerical ratio, insisted that the key to consonance and dissonance lay in the mathematical neatness of these ratios. The Aristoxenians, however, insisted that consonance and dissonance were a matter of human experience. A third group of synthesizers emerged that aimed at reconciling the two approaches: Neoplatonic philosophers. Inheriting the works of these philosophers, scholars of music in the Islamic world set about the task of explaining the mechanisms of apprehension of consonance by human ears according to mathematical rules. In this process, the role of the soul as the link between humanity and the cosmos – with its mathematical underpinnings – gradually grew in emphasis.