The secular tune “L’Homme Arme” (Man of Arms) served as the basis for an astounding number of mass ordinary cycles by all the leading composers of the late 15th Century. Moreover, setting the mass to this tune became an emblem of dynastic membership, and composers from Busnoys to Ockeghem, the elderly Du Fay to the youthful Josquin, used it to pay homage to the tradition (and to best their contemporaries). Here’s a playlist of “Kyrie” settings of the “L’Homme Arme” tune by the four masters listed above, respectively.
The Taruskin Challenge 