Music theorists labelled the musical art of the 1330s and 1340s as 'new' and 'modern'. A close reading of writings on music theory and the polyphonic repertory from the first half of the fourteenth century reveals a modern musical art that arose due to specific innovations in music notation. The French ars nova employed as its theoretical fundament a new system for arranging musical time proposed by the astronomer and mathematician Jean des Murs. Challenging prevailing accounts of the ars nova, this book presents the 'new art' within the intellectual context of its time, revises the datings of Jean des Murs's writings on music theory, and presents the intersection of theory and practice for a crucial era in the history of music. Through contemporaneous accounts, Desmond explores how individuals were involved in 'changing' music in early fourteenth-century France, and the technical developments they pursued that precipitated this stylistic change.

Winner, 2019 Lewis Lockwood Award, American Musicological Society

'Karen Desmond’s book places early fourteenth-century music and musical thought persuasively within their intellectual contexts. Equally at home in music theory, the history of musical style, palaeography, prosopography, astronomy, philosophy and a whole host of other fields of knowledge, she rises to the challenge of saying something substantially ‘new’ about the ars nova. Drawing all these intellectual threads masterfully together, Desmond’s breath taking study will be the defining work on the subject for many years to come.'

Christian Thomas Leitmeir - University of Oxford

'[Karen Desmond gives] an exciting, revisionist account of this crucial period in medieval music history, offering a wealth of new insight into staple texts and works, and a model framework for engaging theory with other modes of intellectual practice. This book will make a significant intervention in the field of fourteenth-century music studies, with repercussions not only for music historians, but also for scholars of intellectual history.'

Emma Dillon - King’s College London

'… [this book] alters our understanding of a crucial moment in music history. Drawing on a dazzling variety of evidence and leading the reader with grace through difficult terrain, the author rethinks what was new in the ars nova. To better see the new art as its contemporaries saw it, the author revises the datings of Jean des Murs’s writings; relates his innovations to developments in astronomy and mathematics; elaborates on the key aesthetic concept of subtilitas; enhances our artistic appreciation of destabilized rhythmic phenomena; and explores the philosophical stakes behind the theoretical controversy, involving two different conceptions of time.'

Source: AMS Awards Committee

‘… deeply engaging … Desmond is meticulous in her presentation of both the theory and the music and the result is a beautifully constructed example of musicological subtilias … Highly recommended.’

Erik W. Goldstrom Source: The Journal of the Association of Anglican Musicians

‘Karen Desmond’s excellent new book … proposes a new way of thinking about the ars nova of fourteenth-century French music … her account will prove an essential contribution to thinking about the period … Thanks to Karen Desmond’s book, we can better see how the ars nova helped create a modern world in the fourteenth century and how it may still be part of that modern world today.’

David Maw Source: Revue de musicologie

‘… the book is a rich cornucopia of materials … that engage the history of science and philosophy as well as musicology and music theory … Desmond has brilliantly teased out many strands relating to this multivalent term [ars nova] and has suggested many avenues for further research.’

Lawrence Earp Source: Plainsong & Medieval Music

‘… there is no question about the importance of this book … Desmond’s book has enhanced this reviewer’s knowledge of the origins and impact of the ars nova immensely … [a] riveting expedition.’

John N. Crossley Source: Parergon