"The most likely reason for the adoption of a relatively small number of discrete intervals as the tonal material for music is that discretization or categorization is a typical, if not universal, strategy used by animals in order to reduce information overload and facilitate processing when subjected to the high-information-conetent signals and/or high information rates from a highly developed sensory system (e.g., Estes, 1972; Terhardt, 1991). An obvious example is the processing of speech information by humans, wherein each language selects a relatively small portion of the available timbral-differences that can be produced by the vocal tract as information-carrying units (phonemes) in the language. A related reason for discrete scales, and another obvious analogy with speech perception, lies in the social aspect of music. Music first developed as, and still largely remains, a social phenomenon associated with religious or other rituals that, like language, necessitated an easily remembered common framework."