It is the vision of the church, from her history, to have the major parts of the Mass sung. The Second Vatican Council assigns a position of pride to the Gregorian chant as the normative form of singing in the Roman liturgy. Traditionally, masses derived their names from the words of the entrance antiphons chants. For example, Funeral Masses were known as Requiem, from the entrance antiphon "Requiem aeternam..." We call the Third Sunday of Advent "Gaudete Sunday," from the first word of the entrance antiphon "Gaudete in domino semper...” When speaking about the parts of Mass, the General Instruction on the Roman Missal (GIRM) uses the word chant instead of song or hymn. The word "chant" has a sacral connotation that the word "song" lacks. Although it is common to hear hymns and songs being used at Mass today, this was not the original intention of the Church. The Mass has its own texts, and these are meant to be chanted. Hymns were originally reserved for the Divine Office or Liturgy of the Hours. Hymn-singing at Mass originated in the custom of the people singing vernacular devotional hymns at Low Mass during the celebrant’s silent recitation of the Latin prayers. It is important to know that the practice of singing hymns at Mass today is because we are omitting some of the Mass chants, namely, the Propers.
According to the original intention of the Church, the most appropriate way of singing at Mass are the Gregorian chants. Because of its solemnity, and because the text is taken directly from sacred scripture, the Gregorian chant is most conducive to the Roman Liturgy. It enables us to pray the Mass and to meditate on the words. Is this a common way of singing today? Absolutely not. We have developed various genres of music, and unfortunately the Gregorian chant has largely been abandoned. We tried to restore it here at our parish, but that did not go well. To my mind, this was due to a number of factors, among which are: insufficient catechesis to prepare parishioners for this change, an unhealthy adherence to the status quo (the “how we have always done it syndrome”), the common resistance to change, regardless of the direction, the absence of a formidable choir to lead this mode of singing, the tone setting that was used, which was only accessible to professional/trained singers, parishioners not having the text of the antiphons so they could follow. The fact that parishioners felt alienated and unable to participate did not help matters either.
It is the mind of the Church that the Antiphons for each liturgy be chanted, either by a cantor, or by the choir and the people in alternating manner. These antiphons are the Introit (Entrance), Gradual (responsorial psalm), Acclamation, Offertory, and Communion. The alternating of the psalm verses and antiphons by both choir and congregation brings out the beauty of this genre of singing in the liturgy, as everyone is raising their voices to God, in unison. The Propers are those parts of Mass that are specific to each liturgy. They change from one Mass to another. For example, the propers of the First Sunday of Advent are different from those of the Second Sunday of Advent. On the other hand, the Ordinary refers to those parts of Mass that do not change. For example, Gloria, Credo, Sanctus, Agnus Dei. These too are chants in their own rights.