Human psychophysiological perception of musical scales and nontraditional music

The physical quantitative background of music mostly assumes a linear behavior, which in real life is not entirely true; while our hearing system, from ear to brain integration processes, also follows nonlinear laws. One may wonder what type of chromatic scale might result from a consideration of the nonlinearities inherent in real physical systems, and to what extent nonlinearities in our physiologic perception of such musical intervals might be directly correlated with what we actually "hear." It is the objective of this article to review some actual musical scales, to recall pre-Hispanic musical instruments and manifestations, and to discuss theoretically some reported and possible human perceptions associated with their sounds. We envision other research avenues that, in the end, may lead to rehabilitation techniques for the handicapped and also to new artistic expressions.