Is it okay or even licit to change the wording, translation, and/or add/remove text of the responsorial psalm in order that it is sung in the fashion of a hymn rather in a chant?
General Instruction of the Roman Missal:
- …Moreover, it is unlawful to substitute other, non-biblical texts for the readings and responsorial Psalm, which contain the word of God.
- …The responsorial Psalm should correspond to each reading and should, as a rule, be taken from the Lectionary.
…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.
- It will be for the competent territorial authority to decide whether certain vernacular texts set to music which have been handed down from former times, can in fact be used, even though they may not conform in all details with the legitimately approved versions of the liturgical texts.
Generally speaking the Psalm should correspond to what is in the Lectionary. However, there are certain exceptions which are approved by the USCCB, the territorial authority, or the local Ordinary.
As long as it has official approval it is OK to use. If it lacks official approval than it should not be used.