ELIZABETH EVA LEACH is Professor of Music at the University of Oxford and a Fellow of the British Academy. Her work focuses on song in the medieval West in the thirteenth and fourteenth centuries. JOSEPH W. MASON is a Junior Research Fellow at New College, University of Oxford. His research focuses on vocal music from the twelfth to the fourteenth century. MATTHEW P. THOMSON is Assistant Professor in Early Music, University College Dublin. Previously a Fitzjames Research Fellow at Merton College, Oxford, his research focuses on music of the thirteenth and fourteenth centuries, including polyphonic motets, monophonic song, and the role of music in literature. ELIZABETH EVA LEACH is Professor of Music at the University of Oxford and a Fellow of the British Academy. Her work focuses on song in the medieval West in the thirteenth and fourteenth centuries. JOSEPH W. MASON is a Junior Research Fellow at New College, University of Oxford. His research focuses on vocal music from the twelfth to the fourteenth century. MATTHEW P. THOMSON is Assistant Professor in Early Music, University College Dublin. Previously a Fitzjames Research Fellow at Merton College, Oxford, his research focuses on music of the thirteenth and fourteenth centuries, including polyphonic motets, monophonic song, and the role of music in literature.