The Tournai Mass: Gloria
The Tournai Mass is the oldest polyphonic Mass to have survived. Dating from 1349, it is preserved in the library of the cathedral of Tournai (Belgium) with identification number A 27 and is dedicated to the Virgin Mary.
It was traditional to 'arrange' sections of the Propers of the Mass in polyphonic style to embelish the religious ceremonies of the great festivals such as Christmas and Easter, but a new practice appeared during the 14th century. The text of the Ordinary of the Mass - the Kyrie, Gloria, Credo, Sanctus and Agnus Dei - was set to music with the intention of creating a cycle: the polyphonic Mass. Many excerpts from such works have survived, but the Tournai Mass is the first complete example to have done so.
The Tournai Mass is a compilation rather than a single unified composition; the various sections are not attributed to any individual composer and they all originate from different places and periods. They were assembled and seem to have been copied out by one particular clerk. The apparent cohesion of the group of pieces is limited to the three-part homophonic writing common to all the pieces except for the final motet. Two types of notations are employed: Franconian or modal notation, characteristic of the Ars Antiqua, used in the Kyrie, Sanctus and Agnus Dei, and mensural notation, showing the clerk's mastery of the innovations brought in with the Ars Nova in the Gloria, Credo and Ite missa est.