Music is a science of melos and of those things contingent to melos. Some define it as follows: "the theoretical and practical art of perfect and instrumental melos"; and others thus: "an art of the seemly in sounds and motions." But we define it more fully and in accordance with our thesis: "knowledge of the seemly in bodies and motions."-Aristides Quintilianus, On Music (1.4), ca. 300 C.E.