Intabulation of a four-voice motet attributed to Gascon, but unidentified. It has been speculted that it might be by Mathieu Gascongne, active early in the sixteenth century. No work of this name is listed in RISM (accessed 5/06/2019). The text is a responsory for Mass on Palm Sunday and is found in MS44.1 of the Cathedral of Toledo, Archivo y Biblioteca Capitular [Cantus ID 600439] among other mainly Spanish sources (see http://cantus.uwaterloo.ca/chant/478982).
A reference that may prove useful is in Barbara Haggh, “An Ordinal of Ockeghem's Time from the Sainte-Chapelle of Paris: Paris, Bibliothèque de l'Arsenal, MS 114”, Tijdschrift van de Koninklijke Vereniging voor Nederlandse Muziekgeschiedenis, Deel 47, No. 1/2, [Johannes Ockeghem] (1997), pp. 33-71.