This project has been truly collaborative from its inception. Both authors had an equal role in the generation of ideas and in the drafting of this book. Each chapter has emerged from research we have undertaken together and have discussed extensively before beginning to write.

Funding for this project was provided by the AHRC/ESRC Religion and Society Programme, the British Academy (through a Small Grant), the Leverhulme Trust (in the form of a Philip Leverhulme Prize), the University of Colorado at Boulder (a sabbatical leave), and the American Musicological Society (a subvention).

We thank the following friends and colleagues, who have given valuable criticism and feedback, asked us stimulating questions, answered inquiries, or shared their work in advance of its publication: Charles Atkinson, Eduardo Henrik Aubert, Ismael Fernández de la Cuesta, William Flynn, Herminio González Barrionuevo, Carmen Julia Gutiérrez González, Andreas Haug, Elaine Hild, Janet Hornby, Luisa Nardini, Edward Nowacki, Andreas Pfisterer, Alejandro Planchart, Don Randel, Susan Rankin, and the anonymous readers for Boydell and Brewer. Colleagues at the University of Bristol (Ed Drewitt, Kevin Kemp, Louisa Slingsby and Eileen Sutton) helped us to develop the graphs. William Hornby helped us to develop the relationship ratios. The Bristol University Music Department Schola Cantorum helped to bring the music to life by performing from the small repertory of chants preserved in heighted notation and from the sixteenth-century Cantorales, and Rebecca Maloy's students from the Spring 2011 Musicology seminar provided valuable feedback on early drafts.