'… 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, Parergon
1. Introduction; 2. Subtilitas and the ars nova; 3. Jean des Murs, Quadrivial Scientist; 4. Arts old and new; 5. From trees to degrees; 6. Notational dots and the line of musical time; Epilogue; Appendix 1: list of transitional ars nova motets and concordances; Appendix 2: key dates in the biography of Jean des Murs; Appendix 3: key dates in the biography of Philippe de Vitry; Appendix 4: sources of Jean des Murs's notitia and conclusiones; Appendix 5: edition of Apta/Flos; Appendix 6: works list for Jean des Murs.