We ourselves are brought into conversation with God by the word of God. The God who speaks in the Bible teaches us how to speak with him ourselves. Particularly in the book of Psalms, he gives us the words with which we can address him, with which we can bring our life, with all its highpoints and lowpoints, into conversation with him, so that life itself thereby becomes a movement towards him. The psalms also contain frequent instructions about how they should be sung and accompanied by instruments. For prayer that issues from the word of God, speech is not enough: music is required. Two chants from the Christian liturgy come from biblical texts in which they are placed on the lips of angels: the Gloria, which is sung by the angels at the birth of Jesus, and the Sanctus, which according to Isaiah 6 is the cry of the seraphim who stand directly before God. Christian worship is therefore an invitation to sing with the angels, and thus to lead the word to its highest destination. Once again, Jean Leclercq says on this subject: “The monks had to find melodies which translate into music the acceptance by redeemed man of the mysteries that he celebrates. The few surviving capitula from Cluny thus show the Christological symbols of the individual modes” (cf. ibid. p. 229).
For Benedict, the words of the Psalm: coram angelis psallam Tibi, Domine – in the presence of the angels, I will sing your praise (cf. 138:1) – are the decisive rule governing the prayer and chant of the monks. What this expresses is the awareness that in communal prayer one is singing in the presence of the entire heavenly court, and is thereby measured according to the very highest standards: that one is praying and singing in such a way as to harmonize with the music of the noble spirits who were considered the originators of the harmony of the cosmos, the music of the spheres. From this perspective one can understand the seriousness of a remark by Saint Bernard of Clairvaux, who used an expression from the Platonic tradition handed down by Augustine, to pass judgement on the poor singing of monks, which for him was evidently very far from being a mishap of only minor importance. He describes the confusion resulting from a poorly executed chant as a falling into the “zone of dissimilarity” – the regio dissimilitudinis. Augustine had borrowed this phrase from Platonic philosophy, in order to designate his condition prior to conversion (cf. Confessions, VII, 10.16): man, who is created in God’s likeness, falls in his godforsakenness into the “zone of dissimilarity” – into a remoteness from God, in which he no longer reflects him, and so has become dissimilar not only to God, but to himself, to what being human truly is. Bernard is certainly putting it strongly when he uses this phrase, which indicates man’s falling away from himself, to describe bad singing by monks. But it shows how seriously he viewed the matter. It shows that the culture of singing is also the culture of being, and that the monks have to pray and sing in a manner commensurate with the grandeur of the word handed down to them, with its claim on true beauty. This intrinsic requirement of speaking with God and singing of him with words he himself has given, is what gave rise to the great tradition of Western music. It was not a form of private “creativity”, in which the individual leaves a memorial to himself and makes self-representation his essential criterion. Rather it is about vigilantly recognizing with the “ears of the heart” the inner laws of the music of creation, the archetypes of music that the Creator built into his world and into men, and thus discovering music that is worthy of God, and at the same time truly worthy of man, music whose worthiness resounds in purity.
Source: Apostolic Journey to France. Address by the Holy Father to the world of Culture