Интроит: Вступительный антифон в литургии

Part of the opening of the liturgical celebration of the Eucharist for many Christian denominations

The Introit is part of the opening of the liturgical celebration of the Eucharist for many Christian denominations. In its most complete version, it consists of an antiphon, psalm verse and Gloria Patri, which are spoken or sung at the beginning of the celebration. It is part of the proper of the liturgy: that is, the part that changes over the liturgical year. In the Roman Rite of the Catholic Church it is known as the antiphona ad introitum (Entrance antiphon), as in the text for each day's Mass, or as the cantus ad introitum (Entrance chant) as in the General Instruction of the Roman Missal, 47 and the First Roman Ordo (sixth to seventh century). In pre 1970 editions of the Roman Missal, the word Introitus was used, distinguished from the normal meaning of the word (entrance) by being capitalized. In Ambrosian chant and Beneventan chant, the counterpart of the Introit is called the ingressa. In the Mozarabic, Carthusian, Dominican, and Carmelite Rites, it is called the "officium". In contemporary Catholic usage, the introit corresponds to the Entrance Antiphon and is sung or recited audibly throughout by the faithful.

The antiphons of most Introits are taken from Psalms, though many come from other parts of Scripture. In some rare cases the antiphon is not from Scripture: "Salve, sancta parens", from the Christian poet Sedulius, who was imitating a line from book V of Virgil's Aeneid, is the antiphon used in the Tridentine form of the Roman Rite for common Masses of the Blessed Virgin Mary; the 1970 revision kept a Mass formula of the Blessed Virgin with that antiphon, but provided several alternatives. The words of the antiphons are related to the theme of the feastday or celebration and most frequently have something in common with the liturgical readings of the Mass. In the Tridentine Mass the Introit is no longer the first text used in the Mass. In Low Mass, the priest reads it only after the Prayers at the Foot of the Altar. Until 1908, even in sung Mass the choir began the Introit only after the priest had begun those prayers, but Pope Pius X restored the old arrangement whereby the Introit accompanied the entrance procession of the priest with the ministers. The Tridentine Mass has the priest read the Introit in the Missal even when it is also sung by the choir. It also has him make the sign of the cross, when reading it, a relic of the time when Mass began with it. If another rite immediately precedes Mass, such as the Palm Sunday procession or the various ceremonies that precede Mass at the Easter Vigil, Mass begins with the collect; there is no Entrance at that point and so no Entrance chant.

In the same way as Church documents are referred to by their incipit (their first words in Latin), Mass formulas are known by the incipit of their Introit, which is the first text in the formula. Thus a Mass for the dead is referred to a Requiem Mass, and the three Christmas Day Masses have been called Dominus dixit, Lux fulgebit and Puer natus. So too, Gaudete Sunday is a name for the third Sunday in Advent, Laetare Sunday for the fourth Sunday in Lent, and Quasimodo Sunday for the Octave or Second Sunday of Easter, because of the incipit of the Entrance antiphons of those Sundays.

In the Anglican Communion, Introit is the name given to the hymn or metrical psalm which is sung at the start of a service, a tradition which dates back to the Book of Common Prayer of 1549, although omitted in the version of 1552 and restored by permission in the reign of Queen Elizabeth I of England.