Yet, from letters which some of you have sent, and from many other sources, We learn that discordant practices have been introduced into the sacred liturgy by your communities or provinces (We speak of those only that belong to the Latin Rite). For while some are very faithful to the Latin language, others wish to use the vernacular within the choral office. Others, in various places, wish to exchange that chant which is called “Gregorian,” for newly-minted melodies. Indeed, some even insist that Latin should be wholly suppressed.
We must acknowledge that We have been somewhat disturbed and saddened by these requests. One may well wonder what the origin is of this new way of thinking and this sudden dislike for the past; one may well wonder why these things have been fostered.
Apostolic Letter, Sacrificium Laudis, of Pope Paul VI, 15 August 1966.