Tactus, Mensuration and Rhythm in Renaissance Music. By Ruth I. DeFord

Abstract

This book is a polished extension and summation that has grown out of articles published over several decades by Ruth DeFord. It is a magisterial achievement; few scholars have engaged as single-mindedly with issues of time measurement from both a theoretical and a practical angle. The result is a model of methodological clarity, clear expository prose, and perceptive musical commentary, communicating an authority born of a deep engagement with both theoretical texts and notated music. As such, it offers a welcome and original perspective on these central aspects of music in the specified period ca. 1420–1600. The book falls into two halves, dealing respectively with theory (historical theoretical texts) and practice (music as notated). The first two chapters in part I address sources of information and the principles of mensural notation; the next five are concerned with subtle and complex expositions of the first term of the book’s title, tactus. They include a thorough and thoroughly useful survey of relevant theorists, with extended texts and translations of pertinent passages. Part II applies the theory to critical and analytical discussions of seven discrete repertories: the songs of Du Fay, the L’homme armé masses of Ockeghem, Busnoys, and Josquin, the five- and six-part motets of Josquin, the Choralis Constantinus of Isaac, the masses of Palestrina, the madrigals of Rore, and “Popular songs and dances.”