49 This should be done especially at the time when catechetical instruction is being given to the Christian people. This may be done more easily and readily in this age of ours than was possible in times past, because translations of the liturgical texts into the vernacular tongues and explanations of these texts in books and pamphlets are available. These works, produced in almost every country by learned writers, can effectively help and enlighten the faithful to understand and share in what is said by the sacred ministers in the Latin language.
Source: Musicae Sacrae (Vatican.va)