Effects of perceptual organization and musical form on melodic expectancies

Abstract

The experiment reported in this chapter examines two aspects of music perception: the role of perceptual organization in generating melodic expectancies, and attentional processing directed at different levels of hierarchical structure in music. The implication-realization model (Narmour, 1990) provides a framework for approaching these questions. It holds that principles of perceptual organization define coherent units within which expectancies operate. The model describes melodic expectancies with five bottom-up principles. The principles are hypothesized to apply not only on the lowest, tone-to-tone level, but also on higher levels between noncontiguous tones. Musical form is described as units at multiple, hierarchically-organized levels. The model holds that when music has similar form, that is, when some characteristics of a pattern are repeated, it draws attention to higher levels. This has the effect of strengthening expectancies operating on higher levels. Thus, musical form is hypothesized to modify the relative strengths of the proposed principles on different levels. An experiment tests these predictions with melodic sequences that contain implications on two levels and exhibit either similar form, AA’, or dissimilar form, AB. The sequences are followed by continuation tones that listeners judge as to whether they are good continuations. These judgments are tested against a numerical coding of the bottom-up principles of the model. The results support the model's principles at both the low and high levels, and confirm the predicted effects of form.