Structure
The Messe de Nostre Dame consists of 5 movements, the Kyrie, Gloria, Credo, Sanctus, and Agnus Dei, followed by the dismissal Ite, missa est. The tenor of the Kyrie is based on Vatican Kyrie IV, the Sanctus and Agnus correspond to Vatican Mass XVII and the Ite is on Sanctus VIII. The Gloria and Credo have no apparent chant basis, although they are stylistically related to one another.[1]
Machaut's Messe de Nostre Dame is for four voices rather than the more common three. Machaut added a contratenor voice that moved in the same low range as the tenor, sometimes replacing it as the lowest voice.