Rhythmic structure in music : a study of the perception of metrical and phrase structure, from a mechanistic viewpoint
The thesis investigates the perception of musical metre and phrasing, which together form a hierarchical rhythmic structure, represented in tree-diagram form. Rather than study human perceptual processes, a mechanistic approach is adopted. It is shown that the most likely rhythmic structure of a passage can be generated largely from the pitch and durational information in scores, through the perception of certain features, termed structural characteristics, supported by some general perceptual preferences. Each characteristic is itself a perceptual preference, capable of selecting certain groupings of notes or chords as phrase groupings or highlighting particular temporally disjunct notes or chords as structural accents, each of which is a potential metrical accent. Mental connections between relatively long notes, a preference for regular metre, and the grouping of relatively close attacks establish a basic (if sometimes ambiguous) rhythmic structure, which may be modified or developed by repetition, a longer-note accompaniment, harmonic rhythm, dissonance and resolution, pitch patterning, and notated dynamics and articulation. Phrase structure influences the perception of tonality, in conjunction with the Harmonic Series, for whose contribution a tonal map is put forward. The characteristics may be temporally congruent or incongruent (cross rhythmic) and are of unequal strength, thus giving rise, in their many different configurations, to further perceptual preferences, which are illustrated by several hundred musical examples. The differences in relative strength permit metre and phrase grouping to be read qualitatively, as a product of the characteristics which generate it.