"The moon of all music, and the light of all singers," was how one contemporary observer described the illustrious 15th-century French composer Guillaume Dufay. Dufay not only enjoyed great acclaim as a musician, but he also enjoyed an unusually long life--he died at 74--which he spent in service to several noble patrons in Italy and as canon of Cambrai Cathedral in France. His music exudes an amazing richness and vitality, due as much to its luminous harmonic writing as to its lively, complex rhythms. The veneration of St. James was of enormous importance in the Middle Ages, signified by the thousands of pilgrimages to the cathedral of Santiago de Compostela in Spain. Dufay's Mass is unusual and remarkable for its stylistic diversity, a feature of the work that's prompted much musicological investigation. For most of us, however, the sheer beauty of the music--exemplified in these resplendent performances--speaks for itself. --David Vernier