KYRIE
The Kyrie is built around the same cantus firmus as the Kyrie from the Faenza Codex sampled in Ex. 9-9:
the famous Cunctipotens genitor melody, which we have encountered by now in several guises. In the
Kyriale, the official book of Ordinary chants, it is assigned to Mass IV, a lavish tenth-century formulary
reserved for feasts of “double” rank. The fact that a setting of it is found in Faenza raises the possibility of
alternatim performance with Machaut’s Kyrie—a kind of responsorial performance in which sections
sung in polyphony alternate with sections played on the organ or sung in plainchant. The Faenza setting is
in fact the earliest presumed documentation of the practice, which became very widespread in the
fifteenth century, especially in Italy and Germany.
EX. 9-16B Guillaume de Machaut, La messe de Nostre Dame, Gloria, final Amen