I have participated in communities of monks and lay people in from Europe to the west Coast of the United States. In all those cases, it is the chanting of the psalms that is transformative for the people involved. It changes us and hopefully conforms us to the likeness of the Lord.
The psalms are important for the celebration of the Liturgy. They are important for entrance chants, Graduals and responsorial psalms, and offertory and communion chants. They are an important part of praying the Mass. Particular liturgies focus on one specific psalm to give a particular focus to the prayer of that Mass. For example, On the First Sunday of Lent, Psalm 90(91) is the text of the Introit, the Gradual and Tract, the Offertory and the Communion. In the Ordinary form it is the Entrance and Communion antiphons as well as the Responsorial Psalm.
The psalms are ancient hymns, laments, ceremonial chants and thanksgiving songs. They contain every emotion known. They are first of all prayer and they teach us to pray. They are supposed to be sung. The music as a vehicle to convey the text, needs to be simple so as not to overtake or obscure the text. The music places the text on our lips and lift our hearts to our generous and merciful God. The ancient modes that have carried the psalms for centuries is the most appropriate. A catholic cantor should be able to chant a psalm on a moment’s notice. That young catholic musicians are ignorant of these modes is a sadness.
These psalms for have been prepared for the Responsorial Psalm for Sundays. They may be useful for any time that prayer is needed.