Excerpts from Musicam Sacram (1967) -- Instruction on Music in the Liturgy -- Sacred Congregation of Rites, March 5, 1967
15. The faithful fulfill their liturgical role by making that full, conscious and active participation which is demanded by the nature of the Liturgy itself and which is, by reason of baptism, the right and duty of the Christian people. This participation:
(a) Should be above all internal, in the sense that by it the faithful join their mind to what they pronounce or hear, and cooperate with heavenly grace,
(b) Must be, on the other hand, external also, that is, such as to show the internal participation by gestures and bodily attitudes, by the acclamations, responses and singing.
The faithful should also be taught to unite themselves interiorly to what the ministers or choir sing, so that by listening to them they may raise their minds to God.
16. One cannot find anything more religious and more joyful in sacred celebrations than a whole congregation expressing its faith and devotion in song. Therefore the active participation of the whole people, which is shown in singing, is to be carefully promoted as follows:
(a) It should first of all include acclamations, responses to the greetings of the priest and ministers and to the prayers of litany form, and also antiphons and psalms, refrains or repeated responses, hymns and canticles. [cf SC30]
(b) Through suitable instruction and practices, the people should be gradually led to a fuller -- indeed, to a complete -- participation in those parts of the singing which pertain to them.
(c) Some of the people's song, however, especially if the faithful have not yet been sufficiently instructed, or if musical settings for several voices are used, can be handed over to the choir alone, provided that the people are not excluded from those parts that concern them…
17. At the proper times, all should observe a reverent silence.
21. Provision should be made for at least one or two properly trained singers, especially where there is no possibility of setting up even a small choir. The singer will present some simpler musical settings, with the people taking part, and can lead and support the faithful as far as is needed…
24. Besides musical formation, suitable liturgical and spiritual formation must also be given to the members of the choir, in such a way that the proper performance of their liturgical role will not only enhance the beauty of the celebration and be an excellent example for the faithful, but will bring spiritual benefit to the choir-members themselves.
47d. Pastors of souls should take care that besides the vernacular "the faithful may also be able to say or sing together in Latin those parts of the Ordinary of the Mass which pertain to them." [SC54]
63. In permitting and using musical instruments, the culture and traditions of individual peoples must be taken into account. However, those instruments which are, by common opinion and use, suitable for secular music only, are to be altogether prohibited from every liturgical celebration and from popular devotions.
64. The use of musical instruments to accompany the singing can act as a support to the voices, render participation easier, and achieve a deeper union in the assembly. However, their sound should not so overwhelm the voices that it is difficult to make out the text; and when some part is proclaimed aloud by the priest or a minister by virtue of his role, they should be silent.
65. In sung or said Masses, the organ, or other instrument legitimately admitted, can be used to accompany the singing of the choir and the people; it can also be played solo at the beginning before the priest reaches the altar, at the Offertory, at the Communion, and at the end of Mass.
The same rule, with the necessary adaptations, can be applied to other sacred celebrations.
66. The playing of these same instruments as solos is not permitted in Advent, Lent, during the Sacred Triduum and in the Offices and Masses of the Dead.
67. It is highly desirable that organists and other musicians should not only possess the skill to play properly the instrument entrusted to them: they should also enter into and be thoroughly aware of the spirit of the Liturgy, so that even when playing ex tempore, they will enrich the sacred celebration according to the true nature of each of its parts, and encourage the participation of the faithful.
