Cantando a música indicada pela Igreja no Graduale Romanum (ou, alternativamente, no Graduale Simplex, nas comunidades que não dispõem de meios humanos para cantar o repertório gregoriano clássico, de acordo com o pedido na Sacrosanctum Concilium, nº 117 e operacionalizado na Instrução Geral do Missal Romano), consegue-se tirar do centro da Liturgia quem lá não deve estar ― o maestro do coro, o padre, a assembleia ― e pôr Cristo no seu lugar próprio, através do uso de textos desde sempre interpretados pela Igreja à luz do acontecimento fulcral da história da humanidade: a Encarnação, Morte e Ressurreição de Deus, em Cristo.
In Roma Locuta Est:
(...) [T]he fact remains that Holy Mother Church has given us a liturgical hymnbook: the Graduale Romanum. In this book, one will find the ancient Gregorian chants. But what many will be surprised to find is that the Church has given us specific chants for every Sunday of the year in the places that we currently sing “hymns.” For any given Mass, there are prescribed chants for the Introit (think here of the “Opening Hymn” you are used to hearing), the Gradual (“Responsorial Psalm”), the Offertorio (“Offertory”), and the Communio (“Communion Song”). Most of these date back more than a thousand years. Of course, in the Graduale Romanum, one will find the chant written in Latin. However, vernacular versions of these exist. What is key is that the liturgical rubrics, while they permit hymns, call for a preference given to these chants. Vatican II itself held that the Gregorian chant tradition should enjoy a “pride of place” in our liturgies.
(...) The surest way to deal with this problem is to give people the sense that they are not the center of reality, nor are they the source. (...) The liturgy is a reality that is given to us, not one that is created by us. In fact, it is in the liturgy itself that we find our own fulfillment. When we go to Mass, we participate in reality itself, something that is much bigger than us. If we see the Liturgy as something that we fit into rather than something that fits into our lives, we can come to understand that we are not the center of reality: God is.
The problem is, as has been observed on several observations over the past decade, there is an increasing narcissism even within the liturgy itself: both priests and people come to think that the liturgy is something that can be created and recreated with the fickle winds of changing culture. (...) What remains to be fixed is the same problem in the hymns that are often chosen for Sunday worship. Many of the modern hymns focus on man rather than God (...). Quite simply, these hymns are self-centered rather than God-centered.
Contrast this with the use of the Graduale Romanum. These chants have been given to us by the Church, each carefully constructed around sacred texts in order to serve as a sort of lectio divina for the readings of the day. (...) Unlike a hymn, which marches forward towards a climactic conclusion, chant allows the listener to rest in contemplation, a mirror of the eternity which we, God willing, will experience someday. But another part is due to the words, which become primary (unlike modern pop music, where the words are often a later add-on to an already existing rhythm/chord structure).
Perhaps the most important point, however, is the fact that the music of the Mass inevitably (forgive the pun) sets the tone of the entire celebration. It stands to reason, then, if we employ a music that is provided for us by the Church (not to mention encouraged by the rubrics), then the people will better understand that the liturgy itself is given and not created. If they come to understand the liturgy, which is the objective center of reality, in this manner, then they will come to see that they are not the center of reality. Thus, my rapid fire, probably incomplete, but hopefully coherent, argument that an antidote for the rise in narcissism is Gregorian Chant. Save the liturgy, save the world.