61. After the first reading comes the responsorial Psalm, which is an integral part of the Liturgy of the Word and holds great liturgical and pastoral importance, because it fosters meditation on the word of God.

The responsorial Psalm should correspond to each reading and should, as a rule, be taken from the Lectionary.

It is preferable that the responsorial Psalm be sung, at least as far as the people’s response is concerned. Hence, the psalmist, or the cantor of the Psalm, sings the verses of the Psalm from the ambo or another suitable place. The entire congregation remains seated and listens but, as a rule, takes part by singing the response, except when the Psalm is sung straight through without a response. In order, however, that the people may be able to sing the Psalm response more readily, texts of some responses and Psalms have been chosen for the various seasons of the year or for the various categories of Saints. These may be used in place of the text corresponding to the reading whenever the Psalm is sung. If the Psalm cannot be sung, then it should be recited in such a way that it is particularly suited to fostering meditation on the word of God.

In the dioceses of the United States of America, the following may also be sung in place of the Psalm assigned in the Lectionary for Mass: either the proper or seasonal antiphon and Psalm from the Lectionary, as found either in the Roman Gradual or Simple Gradual or in another musical setting; or an antiphon and Psalm from another collection of the psalms and antiphons, including psalms arranged in metrical form, providing that they have been approved by the United States Conference of Catholic Bishops or the diocesan Bishop. Songs or hymns may not be used in place of the responsorial Psalm.

159. Songs or hymns that do not at least paraphrase a psalm may never be used in place of the Responsorial Psalm.[129]
...
footnote 129:
See GIRM, no. 61.

41. The effort should be made to ensure that the translations be conformed to that understanding of biblical passages which has been handed down by liturgical use and by the tradition of the Fathers of the Church, especially as regards very important texts such as the Psalms and the readings used for the principal celebrations of the liturgical year; in these cases the greatest care is to be taken so that the translation express the traditional Christological, typological and spiritual sense, and manifest the unity and the inter-relatedness of the two Testaments.[34] For this reason:

a) it is advantageous to be guided by the Nova Vulgata wherever there is a need to choose, from among various possibilities [of translation], that one which is most suited for expressing the manner in which a text has traditionally been read and received within the Latin liturgical tradition;

b) for the same purpose, other ancient versions of the Sacred Scriptures should also be consulted, such as the Greek version of the Old Testament commonly known as the “Septuagint”, which has been used by the Christian faithful from the earliest days of the Church;[35]

c) in accordance with immemorial tradition, which indeed is already evident in the above-mentioned “Septuagint” version, the name of almighty God expressed by the Hebrew tetragrammaton (YHWH) and rendered in Latin by the word Dominus, is to be rendered into any given vernacular by a word equivalent in meaning.

Finally, translators are strongly encouraged to pay close attention to the history of interpretation that may be drawn from citations of biblical texts in the writings of the Fathers of the Church, and also from those biblical images more frequently found in Christian art and hymnody.

[III ON THE PREPARATION OF TRANSLATIONS AND THE ESTABLISHMENT OF COMMISSIONS]
[section] 6. The composition of new liturgical texts in a vernacular language

106. Regarding the composition of new liturgical texts prepared in vernacular languages, which may perhaps be added to those translated from the Latin editiones typicae, the norms currently in force are to be observed, in particular those contained in the Instruction Varietates legitimae.[75] An individual Conference of Bishops shall establish one or more Commissions for the preparation of texts or for the work involved in the suitable adaptation of texts. The texts are then to be sent to the Congregation for Divine Worship and the Discipline of the Sacraments for the recognitio, prior to the publication of any books intended for the celebrants or for the general use of the Christian faithful.[76]

107. It is to be borne in mind that the composition of new texts of prayers or rubrics is not an end in itself, but must be undertaken for the purpose of meeting a particular cultural or pastoral need. For this reason it is strictly the task of the local and national liturgical Commissions, and not of the Commissions treated in nn. 92-104 above. New texts composed in a vernacular language, just as the other adaptations legitimately introduced, are to contain nothing that is inconsistent with the function, meaning, structure, style, theological content, traditional vocabulary or other important qualities of the texts found in the editiones typicae.[77]

108. Sung texts and liturgical hymns have a particular importance and efficacy. Especially on Sunday, the “Day of the Lord”, the singing of the faithful gathered for the celebration of Holy Mass, no less than the prayers, the readings and the homily, express in an authentic way the message of the Liturgy while fostering a sense of common faith and communion in charity.[78] If they are used widely by the faithful, they should remain relatively fixed so that confusion among the people may be avoided. Within five years from the publication of this Instruction, the Conferences of Bishops, necessarily in collaboration with the national and diocesan Commissions and with other experts, shall provide for the publication of a directory or repertory of texts intended for liturgical singing. This document shall be transmitted for the necessary recognitio to the Congregation for Divine Worship and the Discipline of the Sacraments.