Perceptual Organization of Tonal Melody

Tones in a melody possess perceptual qualities that are absent in tones heard in isolation. They are felt to be under the influence of prevailing key and harmony, with certain tones perceived as stable points toward which other, less stable tones are "attracted". At the same time, melodic tones, through their intervallic pattern and motion, establish key and harmony. In this project, we study how the pattern of melodic surface establishes underlying tonal/harmonic structures and how these structures, once established, influence the perceptual organization of subsequent tones. We model this two-way relationship as a dynamic interaction between stimulus-driven (exogenous) neural activities and ongoing (endogenous) activities in pitch memory. The dynamical model of pitch memory explains temporal-order effects found for melodic sequences and provides a psychological basis for traditional music-theoretical concepts and compositional procedures concerning tonal melody. We are also developing an automatic chord estimation system based on the dynamics of pitch memory.