He received his Bachelor from Jesus College, Cambridge, his Masters of Music from King"s College, London, and his Doctor of Philosophy (1978) from University of California, Berkeley.
He is a leader in fifteenth-century music studies, particularly Guillaume Dufay, Josquin des Prez, and secular song. He is an early music performer as a viol player and continuo harpsichordist, performing with the Studio der frühen Musik, Musica Mundana, and Musica Reservata. He taught at University of Manchester starting in 1976, where he is now Emeritus Professor of Musicology.
Visiting appointments include University of Wisconsin, Madison, University of North Carolina, Chapel Hill, École Normale Supérieure, University of Basel, Harvard University and the University of Vienna.
From 2002–2007, he was president of the International Musicological Society.