oa ‘Some Disturbance to the Ear when the Voices Enter’: Invertible Canons at the Octave in Motets by Zarlino and Willaert

Taking as a starting point Gioseffo Zarlino’s concerns in book III, chapter 28 of his Le istitutioni harmoniche about imitative voice entries at the second and other dissonant intervals, this article identifies the little-known compositional technique of invertible canon at the octave in motets by Zarlino and Adrian Willaert. A detailed investigation of these motets provides opportunities to critically appraise Zarlino’s compositional achievements in relation to the constraints of this canonic technique. Zarlino’s approaches are then situated against the novel and thorough-going ways in which his mentor Adrian Willaert employed the same canonic technique. The results of this investigation also draw attention to connections between Zarlino’s theoretical writings and his compositional practice. Through insights into deep underlying compositional principles operating across a selection of works, this study provides new understanding of the history of canon as practised by two eminent sixteenth-century musicians who were central to its development and transmission.