Perceptual and performed accents in musical sequences

Some events in musical sequences are not performed as indicated in the score, but rather undergo systematic timing and intensity variations (played louder/softer and longer/shorter). Traditionally, these performance variations are considered to be related to a musician’s desire to transmit a particular musical interpretation to the listener. We suggest an alternative perceptual explanation that considers that the performance variations may result from constraints of the auditory system, with some events played louder and/or longer because they are heard softer and/or shorter. Two experiments are presented to distinguish between these two explanations. Subjects heard short musical sequences containing rhythmic grouping and melodic accents. Their task was to detect and identify the position of one event that was either slightly longer/shorter (Experiment 1) or louder/softer (Experiment 2) than other events in the sequence. Sensitivity to intensity changes was unaffected by the physical characteristics of the events in the sequences, but sensitivity to duration changes varied in relation to both rhythmic grouping and melodic accents. Thus, these results provide support for the perceptual hypothesis in the case of timing changes, but not for intensity changes.