John Potter's first book, Vocal Authority, was published by Cambridge University Press in 1998, and he is the editor of The Cambridge Companion to Singing (2000). His book Tenor: History of a Voice was published in 2009. He has contributed articles to many academic journals and chapters to other books, including The Cambridge History of Medieval Music (forthcoming) and The Cambridge History of Musical Performance, published in 2012. He is Reader Emeritus in Music at the University of York (having stepped down from his lectureship in 2010 to focus on his portfolio of freelance projects). As a singer John has partnerships with instrumentalists in various parts of the world, notably the Argentinian lutenist and vihuelist Ariel Abramovich, the American medieval harpist Jan Walters and the British electro-acoustic composer Ambrose Field. He also sings with Red Byrd, The Dowland Project (which will release a fourth album in 2012), the Gavin Bryars Ensemble and the German group The Sound and the Fury. His most recent venture is Cantum Pulcriorum Invenire, a research project at the University of Southampton, which will see the release of three CDs of twelfth-century music on Hyperion and a multimedia live version with tenor Christopher O'Gorman and video artist Michael Lynch. John spent 18 years with the Hilliard Ensemble (whose CDs include the million-selling Officium); his complete discography runs to some 150 titles. He also coaches vocal ensembles all over the world, and chairs the ensemble contest jury at the Tampere Vocal Festival (Finland). Neil Sorrell is Senior Lecturer in Music at the University of York. He specialises in Asian music and has written, broadcast and lectured extensively on Indian and Javanese music. He is the author (with the sarangi player, Pandit Ram Narayan) of Indian Music in Performance: A Practical Introduction (1980) and is a recipient of the 1999 Hafiz Ali Khan Award, an international award in recognition of contributions to Indian classical music. He co-founded and directed the English Gamelan Orchestra, the first group of British musicians dedicated to the study, composition and performance of music for the Javanese gamelan. He has composed several pieces for the gamelan and is the author of A Guide to the Gamelan, 2nd edition (2000).