Scalar Shift in Popular Music

Abstract

Existing approaches to scales in popular music do not do justice to the variety of scale collections that are used or to their expressive effects. In this article I propose a novel approach to this problem, focusing particularly on shifts of scale within songs. The idea is simple: The scale-degree content of a song (or a section of a song) tends to occupy a certain region on the “line of fifths,” the circle of fifths stretched out infinitely in both directions. Moving outside this region—especially if the move is emphasized (by rhythmic, textural, or other means) and involves multiple pitch classes—creates a sense of scalar shift. Scalar shifts can be used in a variety of ways: to delineate and reinforce sectional boundaries; to convey a change in mood or situation, simply through the shift itself, or more specifically through sharpward or flatward motion on the line of fifths; to create a momentary effect of surprise or disorientation; or to construct more complex trajectories of tension and resolution.