Sacred Music (Part II)
Liturgical worship is given a more noble form when the divine offices are celebrated solemnJy in song, with the assistance of sacred ministers and the active participation of the people.
The treasure of sacred music is to be preserved and fostered with great care. Choirs must be diligently promoted, especially in cathedral churches; but bishops and other pastors of souls must be at pains to ensure that, whenever the sacred action is to be celebrated with song, the whole body of the faithful may be able to contribute that active participation which is rightly theirs.
-Constitution on the Sacred Liturgy, Sacrosancturn Concilium # 113