The Oxford Dictionary defines leitmotif as a recurrent theme throughout a musical or literary composition, associated with a particular person, idea, or situation. If there is a leitmotif throughout Holy Week, it is the chant Christus Factus Est. For us Christ became obedient unto death, even death on the cross. Therefore God has also exalted him and given him a name which is above every name. Philippians 2:8-9.
This piece is first sung in its entirety at the Eucharist on Palm Sunday. It foreshadows a “panoramic” view of what Christ is about to accomplish for our salvation in the coming week. The opening is low and has a somber quality about it. The word nobis (for us) is given deliberate emphasis. Then, in a beautiful reversal, the word obediens (obedient) leaps up in almost joyful fashion. Emphasis is then given to the word autem (even), leading to crucis ( the cross) — the lowest point of the entire chant. The next sentence is a verse for soloist, in which the melody soars on the phrase exaltavit illum (has exalted him), then gracefully descends in a “rocking” motion to its ending. The first part of the Gradual is then repeated by all.
During the Paschal Triduum, or “three days” leading to Easter, Christus Factus Est appears again — this time during the Divine Office. On Maundy Thursday, only the first phrase is sung at the end of the Office. On Good Friday, parts one and two are chanted, ending on the word crucis (cross), which gives a great sense of finality to the events of this Day of days. On Holy Saturday, we sing the entire piece at the conclusion of the Vigil — almost as a benediction as we ponder Christ’s total giving of himself in the work of our salvation.