On the beat human movement and timing in the production and perception of music

Abstract: This thesis addresses three aspects of movement, performance and perception in music performance. First, the playing of an accent, a simple but much used and practiced element in drumming is studied, second, the perception of gradually changing tempo, and third, the perception and communication of specific emotional intentions through movements during music performance.Papers I and II investigated the execution and interpretation of an accent in drumming, performed under different playing conditions. Players' movements, striking velocities and timing patterns were studied for different tempi, dynamic levels and striking surfaces. It was found that the players used differing movement strategies and that interpreted the accent differently, reflected in their movement trajectories. Strokes at higher dynamic levels were played from a greater average height and with higher striking velocities. All players initiated the accented strokes from a greater height, and delivered the accent with increased striking velocity compared to the unaccented strokes. The interval beginning with the accented stroke was also prolonged, generally by delaying the following stroke. Recurrent cyclic patterns were found in the players' timing performances. In a listening test, listeners perceived grouping of the strokes according to the cyclic patterns.Paper III concerned the perception of gradual tempo changes in auditory sequences. Using an adaptive test procedure subjects judged stimuli consisting of click sequences with either increasing or decreasing tempo, respectively. Each experiment included three test sessions at different nominal tempi (80, 120, and 180~beats per minute). The results showed that ten of the eleven subjects showed an inherent bias in their perception of tempo drift. The direction and magnitude of the bias was consistent between test sessions but varied between individuals. The just noticeable differences for tempo drift agreed well with the estimated tempo drifts in production data, but were much smaller than earlier reported thresholds for tempo drift.Paper IV studied how emotional intent in music performances is conveyed to observers through the movements of the musicians. Three players of marimba, bassoon, and saxophone respectively, were filmed when playing with the expressive intentions Happiness, Sadness, Anger and Fear. Observers rated the emotional content and movement cues in the videos clips shown without sound. The results showed that the observers were able to identify the intentions Sadness, Anger, and Happiness, but not Fear. The rated movement cues showed that an Angry performance was characterized by jerky movements, Happy performances by large, and somewhat fast and jerky movements, and Sad performances by slow, and smooth movements.