In present conditions, what words or melodies could replace the forms of Catholic devotion which you have used until now? You should reflect and carefully consider whether things would not be worse, should this fine inheritance be discarded. It is to be feared that the choral office would turn into a mere bland recitation, suffering from poverty and begetting weariness, as you yourselves would perhaps be the first to experience. One can also wonder whether men would come in such numbers to your churches in quest of the sacred prayer, if its ancient and native tongue, joined to a chant full of grave beauty, resounded no more within your walls. We therefore ask all those to whom it pertains, to ponder what they wish to give up, and not to let that spring run dry from which, until the present, they have themselves drunk deep.
Of course, the Latin language presents some difficulties, and perhaps not inconsiderable ones, for the new recruits to your holy ranks. But such difficulties, as you know, should not be reckoned insuperable. This is especially true for you, who can more easily give yourselves to study, being more set apart from the business and bother of the world. Moreover, those prayers, with their antiquity, their excellence, their noble majesty, will continue to draw to you young men and women, called to the inheritance of our Lord. On the other hand, that choir from which is removed this language of wondrous spiritual power, transcending the boundaries of the nations, and from which is removed this melody proceeding from the inmost sanctuary of the soul, where faith dwells and charity burns – We speak of Gregorian chant – such a choir will be like to a snuffed candle, which gives light no more, no more attracts the eyes and minds of men.
Apostolic Letter Sacrificium Laudis