Bring out the counterpoint: exploring the relationship between implied polyphony and rubato in Bach's solo violin music

Abstract

Performers are consistently instructed to use rubato to `bring out' the implied polyphony in Bach's solo string music. But previous research on the perception of this structural feature suggests that Bach's use of implied polyphony often creates a sense of structural expression, which is something that adds interest to the notes themselves and stands in contrast to the expressive nuances that a performer might later supply. If this is the case, performers could refrain from using much rubato in passages that contain structurally expressive types of implied polyphony, thereby allowing the inherent expression to emerge on its own. In order to test this hypothesis, expert performances from commercial recordings were analyzed to determine the relationship between type of implied polyphony and amount of tempo variation. Initial data confirms that violinists generally avoided any extensive use of rubato in passages where the implied polyphony alters the motivic, metric and/or metric structure and creates this structural expression. Performances of passages containing types of implied polyphony that are less structurally complex or disruptive were then characterized by a more extensive use of rubato that served to `bring out' the contrapuntal structure that was not already inherently expressive.