Harmonic Plateaus in Two Works by Wayne Shorter

Abstract

This essay discusses two pieces by jazz saxophonist and composer Wayne Shorter and examines harmonic regions that serve as plateaus in a composition. The word “plateau” has been selected for its metaphorical strength in communicating a place of rest and consequence. Each plateau influences the structure of the composition and is well established, either through a conventional, functional progression or through another means of prominence. In the former instance, such plateaus are referred to as “tonal plateaus,” in the latter, “prominence plateaus,” while both types belong to the overall category of harmonic plateaus. One compositional method practiced by Shorter is that of employing plateaus to organize harmonic relations. In “Powder Keg,” successive harmonic plateaus with roots a descending third apart initially appear equally autonomous and influential. Upon the arrival of the final chord of the head, the preceding plateaus are recognized as a series of tonicizations of the chord members of this E♭-9 sonority, effecting a linear presentation of the vertical tonic chord. The plateaus are then understood hierarchically as they relate to the home key of the piece. The structure of “El Toro” comprises an equality of four keys with no sonority or tonal region exhibiting fundamental influence over the composition as a whole. The harmonic (tonal) plateaus in “El Toro” do not reveal themselves to be part of a larger tonal scheme, but instead are self-sufficient and irreducible. Thus within the tonal plateaus are functional harmonic relations used to establish the various keys, while the nonfunctional relations between the plateaus result in a nontonal composition.