Reassessing the Plagal Cadence in Byrd and Morley

Abstract

Many sixteenth-century contrapuntal works include prominent “plagal” cadences—phrase- and section-ending passages with bass descent by fourth or ascent by fifth. But these plagal cadences lack the characteristic melodic formulas that were essential for defining other cadences. Accordingly, they proved enigmatic for sixteenth-century theorists, who mostly declined to describe them, and they remain problematic for contemporary analysts, who have not reached consensus on the origins, purpose, or tonal focus of these cadences. This article presents new evidence from the vocal music of William Byrd and the theoretical writing of Thomas Morley of a nascent theory of plagality in late-sixteenth-century England. Morley’s extensive catalogue of cadences—famously copied from Tigrini—includes a number of plagal cadences that were not found in his source. Instead, Morley’s supplementary plagal cadences reflect the variety of cadential structures in contemporary practice, as exemplified by the music of Byrd, Morley’s teacher. The article identifies three distinct uses of plagality in Byrd’s corpus: terminal plagal cadences, terminal “half” cadences, and phrase-bisecting dominants.