A contemporary theorist credits Antoine Busnois with composition of the tune L'homme armé (The Armed Man). The jaunty tune contains evocations of trumpet calls, and the text translates roughly: "Fear the armed man; word has gone out that everyone should arm himself with a haubregon [chainmail coat] of iron." This little piece, which seems to refer to a crusade against the Turks—and may have particular relevance to Busnois' patron Charles the Bold, Duke of Burgundy—became the single most popular borrowed melody for the composition of masses in the Renaissance period. Including those of Busnois, who wrote at least one such mass and perhaps six more, Ockeghem, and Palestrina, over 30 L'homme armé masses survive. Two by Josquin Desprez were written by 1502; the earlier but more intellectually virtuosic, is subtitled super voces musicales, as it presents the borrowed tune on every musical voice (pitch) of the scale in turn.

Josquin takes as his precompositional scaffolding a mild elaboration of the L'homme armé tune, and quotes this as a cantus firmus underlying each movement of the Mass; however, though the notes remain the same, each time he manipulates the structure in new and clever ways. The Kyrie movement gives the cantus firmus to the tenor voice, centered on the pitch C, one time through. The Gloria and Credo each move the cantus firmus tune up one pitch (to D and E, respectively); both also give the structural voice twice through, once forwards, and once in retrograde motion. In the Sanctus, the tenor sings the L'homme armé melody beginning on F; on the jubilant text "Hosanna," the note values are diminished such that the structural function is masked. Agnus Dei I continues the climactic rise to the pitch G; Agnus Dei II begins as if the cantus firmus is present on "A," but proceeds to a freely composed trio. Agnus Dei III places the now-familiar tune in extremely long notes sung by the highest voice, beginning on "A," with an indication instructing the soprano to "sing without ceasing"—that is, without rests. The other three voices in this movement sing tight, motivic, imitative passages around the climactic top voice.

The intellectual complexity of the Mass is heightened by a number of manipulations Josquin performs on the mensuration (rhythmic organization). The very first sounds heard in the first Kyrie present the L'homme armé tune in imitation between three voices, but as a mensuration canon: each voice interprets the notes in a different time signature. Later, in the freely composed Benedictus, Josquin completes a separate mensuration canon in each of the three duos. And every time that the outer three voices are singing in duple meter, the cantus firmus remains in its triple meter, creating a delightful polyrhythm.

As mentioned above, this L'homme armé Mass is only one in a long lineage. Ockeghem reacted to the Busnois' original L'homme armé Mass by trying to make his own setting more complex and clever than the music of the elder master; here Josquin Desprez leaps into an emerging contest of compositional skills, and trumps all comers.

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