Q: Can the psalm after the first reading (usually from the Old Testament) be replaced by a hymn related to the second reading (usually from the New Testament) or the Gospel? Music groups rarely have a repertoire that includes all the psalms, but can usually find something related to the second reading or Gospel. — J.S., London
A: The short answer to this question is no. The General Instruction of the Roman Missal (GIRM, American translation) is quite explicit in No. 61, which deals with the psalm:
«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.»
Thus, although there is a lot of flexibility in order to promote singing the psalm, including the substitution of the psalm of the day and possible use of an approved metrical version, there is no occasion in which a non-biblical hymn may substitute the psalm.
This is because no human work, no matter now musically or poetically accomplished, can substitute God’s inspired word. This norm is already found in the GIRM, No. 57:
«In the readings, the table of God’s word is prepared for the faithful, and the riches of the Bible are opened to them. Hence, it is preferable to maintain the arrangement of the biblical readings, by which light is shed on the unity of both Testaments and of salvation history. Moreover, it is unlawful to substitute other, non-biblical texts for the readings and responsorial Psalm, which contain the word of God.»
Only God’s Word enjoys that special presence of Christ which is found during the liturgical proclamation of the Word. As St. Augustine wrote in his lectures on the Gospel of John (30,1):
«The passage of the holy Gospel of which we have before discoursed to you, beloved, is followed by that of today, which has just now been read. Both the disciples and the Jews heard the Lord speaking; both men of truth and liars heard the Truth speaking; both friends and enemies heard Charity speaking; both good men and bad men heard the Good speaking. They heard, but He discerned; He saw and foresaw whom His discourse profited and would profit. Among those who were then, He saw; among us who were to be, He foresaw. Let us therefore hear the Gospel, just as if we were listening to the Lord Himself present: nor let us say, O happy they who were able to see Him! because there were many of them who saw, and also killed Him; and there are many among us who have not seen Him, and yet have believed. For the precious truth that sounded forth from the mouth of the Lord was both written for our sakes, and preserved for our sakes, and recited for our sakes, and will be recited also for the sake of our prosperity, even until the end of the world. The Lord is above; but the Lord, the Truth, is also here. For the body of the Lord, in which He rose again from the dead, can be only in one place; but His truth is everywhere diffused. Let us then hear the Lord, and let us also speak that which He shall have granted to us concerning His own words.»
God speaks to us through all the readings and not just the Gospels. We also respond to him using his inspired words which encapsulate all possible human reactions to the encounter with God.