Intervals, Scales, and Tuning

Publisher Summary The chapter discusses the possible origins and bases of scales including those aspects of scales that are universal across musical cultures. It also addresses the perception of the basic unit of melodies and scales, the musical interval. Natural intervals are define as intervals that show maximum sensory consonance and harmony, have influenced the evolution of the scales of many musical cultures, but the standards of intonation for a given culture are the learned interval categories of the scales of that culture. Based on the results of musical interval adjustment and identification experiments, and on measurements of intonation in performance, the intonation standard for Western music appears to be a version of the equitempered scale that is slightly compressed for small intervals, and stretched for wide intervals, including the octave. The perception of musical intervals shares a number of commonalities with the perception of phonemes in speech, most notably categorical-like perception, and an equivalence of spacing, in sensation units, of categories along the respective continua. However, the perception of melodic musical intervals appears to be the only example of ideal categorical perception in which discrimination is totally dependent on identification. Therefore this chapter concludes that, rather than speech being “special” as ofttimes proclaimed by experimental psychologists it seems that music is truly special.