Part III of Chapter III gets a bit into the singing of the psalms. Don’t worry; GILH has a whole section (267-284) outlining singing in greater detail. For now we’ll peek a bit into singing psalms over the next five sections.
121. Different psalms may be sung in different ways for a fuller grasp of their spiritual meaning and beauty. The choice of ways is dictated by the literary genre or length of each psalm, by the language used, whether Latin or the vernacular, and especially by the kind of celebration, whether individual, with a group, or with a congregation. The reason for using psalms is not the establishment of a fixed amount of prayer but their own variety and the character proper to each.
These are practical considerations. One important one is that the music fits the genre of the psalm. I’m not convinced composers always have this consideration in mind when writing for the liturgy.
122. The psalms are sung or said in one of three ways, according to the different usages established in tradition or experience: directly (in diredum), that is, all sing the entire psalm, or antiphonally, that is, two choirs or sections of the congregation sing alternate verses or strophes, or responsorially.
The structure and style of the psalm often suggest which of these ways is most suitable.
123. At the beginning of each psalm its own antiphon is always to be recited, as noted in nos. 113-120. At the end of the psalm the practice of concluding with the Glory to the Father and As it was in the beginning is retained. This is the fitting conclusion endorsed by tradition and it gives to Old Testament prayer a note of praise and a Christological and Trinitarian sense. The antiphon may be repeated at the end of the psalm.
Did you know that the antiphon “may” be repeated, and that the concluding doxology is also an appropriate ending?