Source: TrentC 88, fols. 85v-93r (c.1456-62). The musical text is in many places (especially the Crucifixus) corrupt beyond secure reconstruction. I have tidied up the counterpoint where absolutely necessary, but have left some infelicities of part-writing as transmitted, even though they may well reflect scribal error rather than authorial intent.
Stylistically this could easily be a setting by Johannes Ockeghem. Only Gloria, Credo, and Sanctus survive. Based on anonymous 3 voice chanson "Puisque m'amour" (see http://elvis.music.mcgill.ca/node/676).