The Communion is the Gregorian chant

Gregorian chant

Gregorian chant is the central tradition of Western plainchant, a form of monophonic liturgical music within Western Christianity that accompanied the celebration of Mass and other ritual services...

 sung during the distribution of the Eucharist

Eucharist (Catholic Church)

"At the Last Supper, on the night he was betrayed, our Savior instituted the Eucharistic sacrifice of his Body and Blood."...

 in the Roman Rite

Roman Rite

The Roman Rite is the liturgical rite used in the Diocese of Rome in the Catholic Church. It is by far the most widespread of the Latin liturgical rites used within the Western or Latin autonomous particular Church, the particular Church that itself is also called the Latin Rite, and that is one of...

 Catholic Mass

Mass (liturgy)

"Mass" is one of the names by which the sacrament of the Eucharist is called in the Roman Catholic Church: others are "Eucharist", the "Lord's Supper", the "Breaking of Bread", the "Eucharistic assembly ", the "memorial of the Lord's Passion and Resurrection", the "Holy Sacrifice", the "Holy and...

. It is one of the antiphonal chants of the Proper

Proper (liturgy)

The Proper is a part of the Christian liturgy that varies according to the date, either representing an observance within the Liturgical Year, or of a particular saint or significant event...

 of the Mass, and the final chant in the proper. It is followed by the Post-Communion.

Since it is part of the Proper of the Mass and changed according to the Mass, the most common musical settings of it are for special Masses such as Requiem

Requiem

A Requiem or Requiem Mass, also known as Mass for the dead or Mass of the dead , is a Mass celebrated for the repose of the soul or souls of one or more deceased persons, using a particular form of the Roman Missal...

 Masses, where the chant has the incipit

Incipit

Incipit is a Latin word meaning "it begins". The incipit of a text, such as a poem, song, or book, is the first few words of its opening line. In music, it can also refer to the opening notes of a composition. Before the development of titles, texts were often referred to by their incipits...

 Lux aeterna

Lux Aeterna (disambiguation)

Lux Aeterna may refer to:* Lux Aeterna, Latin for eternal light.In music:* Lux Aeterna , album by woodwind player Dave Fitzgerald* Lux Aeterna , album by guitarist Terje Rypdal...

.

In contemporary Catholic usage

Mass of Paul VI

The Mass of Pope Paul VI is the liturgy of the Catholic Mass of the Roman Rite promulgated by Paul VI in 1969, after the Second Vatican Council...

, the communion chant corresponds to the Communion Antiphon and is sung or recited audibly throughout by the faithful.

The text is ordinarily from a psalm.