The Christe is the middle section of the tripartite Kyrie; most polyphonic Christe settings use a reduced texture of two or three voices. Obrecht, however, employs all four voices, relying on a change from triple to duple time for contrast. He also repeats the first phrase of the cantus firmus introduced in the first Kyrie, but intensified in interesting ways. First, the chant in the tenor voice is transposed up from G to D, so that the tenor in this section is actually higher in pitch than the alto. Second, by placing the soprano in the lowest part of his range at the the entrance of the cantus firmus, the chant melody is made to stand out as the highest sounding voice. Finally. the first phrase of the chant is then repeated at twice its original speed, again as the highest sounding voice. These strategies foreground the appeal to St. Donatian, here joined with the Greek plea directed to Jesus Christ.
For more information, see:
Hiley, David. Western Plainchant: a Handbook. Oxford: Oxford University Press. 1993. See in particular pp. 150-56, 211-13.
Crocker, Richard L. “Kyrie eleison.” Grove Music Online. 10 Jul. 2018. www.grovemusiconline.com
Strohm, Reinhard. Music in Late Medieval Bruges. Oxford: Clarendon Press. 1985. See in particular pp.38-42.
Wegman, Rob C. Born for the Muses: The Life and Masses of Jacob Obrecht. Oxford: Oxford University Press, 1994. See in particular pp.169-74.