“…The reasons for this shift must probably be sought in the rise of lay piety and the consequent increase in secular patrons that characterized the fourteenth and the fifteenth century. An anonymous composition of English origin, the so-called "Caput Mass" (named after a chant melisma on the word "caput" from which it draws its musical and symbolic structure ;Robertson 2006), by the 1440s paradigmatically introduced the use of a pre-existing melody ("cantus firmus"), a technique borrowed from the motet that could serve as a unifying device linking the five Ordinary movements into an ordered whole. An isolated full set survives by Machaut.…”