Possibly by Antoine Busnoys. Edition: Antoine Busnoys, Collected Works, ed. Richard Taruskin, 3 vols. (New York: The Broude Trust, 1990), 2: 000-000. Source used for this recording: TrentC 89, fols. 318v-330r (c.1460-63). Dates are start of Wegman's database and the date for TrentC 89. Based on 3-voice chanson "Quant ce viendra" by Busnoys, Ockeghem, or anonymous (http://elvis.music.mcgill.ca/node/1057). Agnus dei missing in Wegman.