When setting these parts of the Mass to music, fidelity to the texts must be followed. The music must fit the official prayers of the Church; not the other way around. The documents make that clear. According to Redemptionis Sacramentum:
[59.] The reprobated practice by which Priests, Deacons or the faithful here and there alter or vary at will the texts of the Sacred Liturgy that they are charged to pronounce, must cease. For in doing thus, they render the celebration of the Sacred Liturgy unstable, and not infrequently distort the authentic meaning of the Liturgy.Sacrosanctum Concilium, the Constitution on the Sacred Liturgy, which was promulgated by Pope Paul VI in 1963, specifically states that:
Therefore no other person, even if he be a priest, may add, remove, or change anything in the Liturgy on his own authority.Sadly, it seems to me that some composers have taken it upon themselves to do just that, altering the texts of the official liturgical prayers of the Church in their pieces. One such setting that comes to mind is the "Mass of Creation", which seems to take liberties with both the Sanctus and the Agnus Dei. While "God of power, God of might" may seem minor, the composer takes it upon himself to edit the official texts of the Church. Why could he not simply retain "God of power and might"? The "and" could have been stretched a little to fit the piece. Another anamoly from the same setting comes from the Agnus Dei. Now, there are certain parts of the Roman Missal where the celebrant is given some flexibility whenever the text reads "these or similar words." However, this phrase only pops up in a couple of instances. "These or similar words" does not spread accross the board to the parts of the Mass. The Roman Missal does not have extra "acclamations" for the Agnus Dei (Lamb of God). The official text reads:
Lamb of God, you take away the sins of the world, have mercy on us.The Roman Missal does not have an asterisk indicating that other titles such as "Prince of Peace" or "Bread of Life" could be used. It does not even have provisions for the Holy Name of Jesus to be included in the Agnus Dei.
Lamb of God, you take away the sins of the world, have mercy on us.
Lamb of God, you take away the sins of the world, grant us peace.
Unfortunately, this trend is not confined to the English language. Spanish-language settings also have their share of problems as well. In some settings, the Gloria is shortened and paraphrased to the point that the prayer is unrecognizable, save for the first line. A couple of the Sanctus settings have strange phrases inserted into the prayer. One Spanish-language Agnus Dei setting lumps the whole litany together while the cantor sings "O Pan de Vida" and "O Santa Copa" in harmony.
The Church gives us these official texts for a reason. These are the prayers of the Mass that we are to use. We cannot simply take them and edit them as we please. When we start to add or delete the wording of these prayers to suit our own needs, trying to put our own "creative stamp" on things, we do a disservice to the Church and to the faithful.
I am hopeful that the revised translations will force composers to work around the texts and make the music fit the prayer, instead of the other way around. Composers should be at the service of the Liturgy, not the other way around.