L'homme armé
Showing off his contrapuntal virtuosity seems to be Josquin's aim, and the mass is full of mensuration canons, second only to Ockeghem's "Missa prolationum", which contains nothing "but" mensuration canons. In a mensuration canon, each voice sings the same notes, but the length of time each note is sung differs. The opening Kyrie of Josquin's mass contains consecutive mensuration canons based on each phrase of the L'homme armé tune, with the tenor leading each and the other voices entering in turn. The second of the three of Agnus Dei sections is another well-known mensuration canon (see example); this particular canon was famous in the sixteenth century, and often mentioned in theoretical treatises.