The Tractatus de tonis of Guy of Saint-Denis (written ca. 1300-10)differs from other treatises on plainchant in the depth of its analysis of thevarious tones into which chant was traditionally classified. The treatise ofGuy of Saint-Denis is preserved as the concluding item in an anthology of textsabout plainchant that Guy compiled (now London, British Library, MS Harley281), beginning with some writings of Guido of Arezzo and a Cistercian tonary,but also including the Ars musice ofJohannes de Grocheio and the Tractatus detonis of Petrus de Cruce. Guy's treatise presents itself as a syntheticoverview of both the theory and practice of plainchant in a way that combinesthe very practical reflection of Guido of Arezzo with ideas of more Aristoteleianinspired theorists such as Johannes de Grocheio and Peter of Auvergne.
Constant J. Mews is Director of the Centre for Religious Studies, Monash University in Victoria, Australia. Carol J. Williams is a Senior Lecturer at Monash University, specializing in medieval music. John N. Crossley is a Professor Emeritus at Monash University. Catherine Jeffreys is an Adjunct Research Associate at Monash University.
AcknowledgmentsAbbreviationsIntroductionOutline of the Tractatus de tonisTractatus de tonis: Text and TranslationAppendicesI. Deleted materialII. Explanatory materialWorks CitedManuscript sourcesPrimary sourcesSecondary sourcesLexiconGlossaryOnomastic Index
"This important publication increases the accessibility of a less-well-known medieval treatise on music theory devoted to the Gregorian chant repertoire for Mass and Office. [...] This welcome new edition and English translation of the Tractatus by a team of Australian scholars introduces the treatise by identifying the sources of Guy's teaching, sketching the history of his abbey in the late thirteenth and early fourteenth centuries, and exploring the treatise's relationship to the Cistercian and Dominican chant traditions." Joseph Dyer, The Medieval Review 18.03.18