Celtic chant is thought have been superseded from the eleventh century, as elsewhere in Europe, by more complex Gregorian chant. The version of this chant linked to the liturgy as used in the Diocese of Salisbury, the Sarum Use, first recorded from the thirteenth century, became dominant in England and was the basis for most surviving chant in Scotland. It was closely related to Gregorian chant, but it was more elaborate and with some unique local features. The Sarum rite continued to be the basis of Scottish liturgical music in Scotland until the Reformation and where choirs were available, which was probably limited to the great cathedrals, collegiate churches and the wealthier parish churches it would have been used in the main ingredient of divine offices of vespers, compline, matins, lauds, mass and the canonical hours. In the later Middle Ages, the development of the doctrine of purgatory and the proliferation of altars meant that this music would have been joined by large numbers of requiem masses, designed to speed the souls of the dead to heaven, although no traces of these masses have survived. Over 100 collegiate churches of secular priests were founded in Scotland between 1450 and the Reformation. They were designed to provide masses for their founders and their families, who included the nobility and the emerging orders of the Lords of Parliament and the wealthy merchants of the developing burghs. From the thirteenth century, Scottish church music was increasingly influenced by continental developments, with figures like the musical theorist Simon Tailler studying in Paris, before returned to Scotland where he introduced several reforms of church music. The "Wolfenbüttel 677" manuscript contains a large number of French compositions, particularly from Notre Dame de Paris, beside inventive pieces by unknown Scottish composers. Monophony was replaced from the fourteenth century by the "Ars Nova", a movement that developed in France and then Italy, replacing the restrictive styles of Gregorian plainchant with complex polyphony. The tradition was well established in England by the fifteenth century. The distinctive English version of polyphony, known as the "Contenance Angloise" (English manner), used full, rich harmonies based on the third and sixth, which was highly influential in the fashionable Burgundian court of Philip the Good, where the Burgundian School associated with Guillaume Dufay developed. In the late fifteenth century a series of Scottish musicians trained in the Netherlands before returning home, including John Broune, Thomas Inglis and John Fety, the last of whom became master of the song school in Aberdeen and then Edinburgh, introducing the new five-fingered organ playing technique.