Christus factus est (“Christ became”) is the gradual chant for the Mass of Maundy Thursday, and is based on Phillip 2:8-9.
Dom Gueranger explains the chant: “The gradual is made up of those admirable words, which the Church so often repeats during these three days, and by which St. Paul warms us to gratitude towards the Son of God, who delivered himself up for us.” (1)
Christus factus est is here interpreted by Pro Cantione Antiqua.
Listen to Christus factus est
Christus factus est pro nobis
Obediens usque ad mortem,
Mortem autem crucis. V. Proper quod et Deus exaltavit illum,
Et dedit illi nomen,
Quod est super omne nomen.
Christ became for us
Obedient unto death,
Even to the death of the cross. V. For this cause God also hath exalted Him,
And hath given Him a name,
That is above all names.
Dom Gueranger, The Liturgical Year, Loreto Publications, 2000, vol. 6, p. 378.