Music of the fifteenth century shows a change in style, the origin of which contemporary historical and theoretical sources place in England. At the same time as English characteristics appear in the music of the new style, the ideas of humanism spead throughout Europe. However, both developments are difficult to grasp in musical terms; broadly speaking they are related to a new perception of music as sound (rather than arithmetic) and to the regional and temporary delimitation of the new style. The life, work and environment of John Dunstaple lend themselves to explore these developments, as his name is often mentioned in relation to the new style in theoretical writings of the fifteenth century, and in musical sources it is used as a marker for the English origin of a composition.