The 15th century shows a change in style in music, the origin of which is seen in contemporary historical and theoretical sources in England. Simultaneously with the adoption of English features in the music of the new style, from Italy the ideas of humanism spread throughout Europe. Both developments, however, are elusive in music; in the broadest sense, they are related to the perception of music as sound as well as to the spatial and temporal delimitation of the new style. The life, work and environment of John Dunstaple are ideal for examining these developments, because his name is often mentioned in the theoretical writings of the 15th century in connection with the emergence of the new style and in the musical sources it is almost a synonym for his English origin a composition.