This topic has been debated in our parish for some time, mostly by me. I would appreciate if someone has the definative answer whether or not it is permissible to change the wording of the Psalms during Mass. I am not asking if it is okay to simply change the authorized reading. I am asking, is it permissible to change whole texts of the Psalms? In other words, make something up. I addition to the answer, I would appreciate verse and chapter to support the answer. Thank you.
From the GIRM:
In the Dioceses of the United States of America, instead of the Psalm assigned in the Lectionary, there may be sung either the Responsorial Gradual from the Graduale Romanum, or the Responsorial Psalm or the Alleluia Psalm from the Graduale Simplex, as described in these books, or an antiphon and Psalm from another collection of Psalms and antiphons, including Psalms arranged in metrical form, providing that they have been approved by the Conference of Bishops or the Diocesan Bishop. Songs or hymns may not be used in place of the Responsorial Psalm.
See GIRM 57-61
Beat me to it!
Thank you to everyone for your answers, they have been most helpful.