It is well known the Church demands something of believers before they receive the sacraments. Something of this is described in this section of the GILH:
104. To sing the psalms with understanding, then, is to meditate on them verse by verse, with the heart always ready to respond in the way the Holy Spirit desires. The one who inspired the psalmist will also be present to those who in faith and love are ready to receive his grace. For this reason the singing of psalms, though it demands the reverence owed to God’s majesty, should be the expression of a joyful spirit and a loving heart, in keeping with their character as sacred poetry and divine song and above all with the freedom of the children of God.
The nature of the psalms is for the one praying them to possess an interior joy and love so as to worthily sing them. I don’t know that we church musicians realize this often enough. Reverence is only the first step to being a psalmist or even a participating worshipper. None of us would be perfect in this regard, but looking to cultivate these virtues with regard to one’s musicianship, one’s relationship in the faith community, and one’s approach to the Church would seem to be a wise undertaking.