General Instruction of the Roman Missal: Chapter II, The Structure of the Mass, Its Elements and Its Parts
III. The Individual Parts of the Mass
A. The Introductory Rites
46The rites preceding the Liturgy of the Word, namely the Entrance, Greeting, Act of Penitence, Kyrie, Gloria, and collect, have the character of a beginning, introduction, and preparation.
Their purpose is to ensure that the faithful who come together as one establish communion and dispose themselves to listen properly to God’s word and to celebrate the Eucharist worthily.
In certain celebrations that are combined with Mass according to the norms of the liturgical books, the Introductory Rites are omitted or performed in a particular way.
The Entrance
47After the people have gathered, the Entrance chant begins as the priest enters with the deacon and ministers. The purpose of this chant is to open the celebration, foster the unity of those who have been gathered, introduce their thoughts to the mystery of the liturgical season or festivity, and accompany the procession of the priest and ministers.
48The singing at this time is done either alternately by the choir and the people or in a similar way by the cantor and the people, or entirely by the people, or by the choir alone. In the dioceses of the United States of America there are four options for the Entrance Chant: (1) the antiphon from The Roman Missal or the Psalm from the Roman Gradual as set to music there or in another musical setting; (2) the seasonal antiphon and Psalm of the Simple Gradual; (3) a song from another collection of psalms and antiphons, approved by the Conference of Bishops or the diocesan Bishop, including psalms arranged in responsorial or metrical forms; (4) a suitable liturgical song similarly approved by the Conference of Bishops or the diocesan Bishop.[55]
If there is no singing at the entrance, the antiphon in the Missal is recited either by the faithful, or by some of them, or by a lector; otherwise, it is recited by the priest himself, who may even adapt it as an introductory explanation (cf. no. 31).
Greeting of the Altar and of the People Gathered Together
49When they reach the sanctuary, the priest, the deacon, and the ministers reverence the altar with a profound bow.
As an expression of veneration, moreover, the priest and deacon then kiss the altar itself; as the occasion suggests, the priest also incenses the cross and the altar.
50When the Entrance chant is concluded, the priest stands at the chair and, together with the whole gathering, makes the Sign of the Cross. Then he signifies the presence of the Lord to the community gathered there by means of the Greeting. By this Greeting and the people’s response, the mystery of the Church gathered together is made manifest.
After the greeting of the people, the priest, the deacon, or a lay minister may very briefly introduce the faithful to the Mass of the day.
The Act of Penitence
51Then the priest invites those present to take part in the Act of Penitence, which, after a brief pause for silence, the entire community carries out through a formula of general confession. The rite concludes with the priest’s absolution, which, however, lacks the efficacy of the Sacrament of Penance.
On Sundays, especially in the Season of Easter, in place of the customary Act of Penitence, from time to time the blessing and sprinkling of water to recall Baptism may take place.[56]
The Kyrie Eleison
52After the Act of Penitence, the Kyrie is always begun, unless it has already been included as part of the Act of Penitence. Since it is a chant by which the faithful acclaim the Lord and implore his mercy, it is ordinarily done by all, that is, by the people and the choir or cantor having a part in it.
As a rule, each acclamation is sung or said twice, though it may be repeated several times, by reason of the character of the various languages, as well as of the artistry of the music or of other circumstances. When the Kyrie is sung as a part of the Act of Penitence, a trope may precede each acclamation.
The Gloria
53The Gloria is a very ancient and venerable hymn in which the Church, gathered together in the Holy Spirit, glorifies and entreats God the Father and the Lamb. The text of this hymn may not be replaced by any other text. The Gloria is intoned by the priest or, if appropriate, by a cantor or by the choir; but it is sung either by everyone together, or by the people alternately with the choir, or by the choir alone. If not sung, it is to be recited either by all together or by two parts of the congregation responding one to the other.
It is sung or said on Sundays outside the Seasons of Advent and Lent, on solemnities and feasts, and at special celebrations of a more solemn character.
The Collect
54Next the priest invites the people to pray. All, together with the priest, observe a brief silence so that they may be conscious of the fact that they are in God’s presence and may formulate their petitions mentally. Then the priest says the prayer which is customarily known as the collect and through which the character of the celebration is expressed. In accordance with the ancient tradition of the Church, the collect prayer is usually addressed to God the Father, through Christ, in the Holy Spirit,[57] and is concluded with a trinitarian ending, that is to say the longer ending, in the following manner:
If the prayer is directed to the Father: Per Dominum nostrum Iesum Christum Filium tuum, qui tecum vivit et regnat in unitate Spiritus Sancti, Deus, per omnia saecula saeculorum (Through our Lord, Jesus Christ, your Son, who lives and reigns with you and the Holy Spirit, one God, forever and ever);
If it is directed to the Father, but the Son is mentioned at the end: Qui tecum vivit et regnat in unitate Spiritus Sancti, Deus, per omnia saecula saeculorum (Who lives and reigns with you and the Holy Spirit, one God, forever and ever);
If it is directed to the Son: Qui vivis et regnas cum Deo Patre in unitate Spiritus Sancti, Deus, per omnia saecula saeculorum (You live and reign with God the Father in the unity of the Holy Spirit, one God, forever and ever).
The people, uniting themselves to this entreaty, make the prayer their own with the acclamation, Amen.
There is always only one collect used in a Mass.
B. The Liturgy of the Word
55The main part of the Liturgy of the Word is made up of the readings from Sacred Scripture together with the chants occurring between them. The homily, Profession of Faith, and Prayer of the Faithful, however, develop and conclude this part of the Mass. For in the readings, as explained by the homily, God speaks to his people,[58] opening up to them the mystery of redemption and salvation, and offering them spiritual nourishment; and Christ himself is present in the midst of the faithful through his word.[59] By their silence and singing the people make God’s word their own, and they also affirm their adherence to it by means of the Profession of Faith. Finally, having been nourished by it, they pour out their petitions in the Prayer of the Faithful for the needs of the entire Church and for the salvation of the whole world.
Silence
56The Liturgy of the Word is to be celebrated in such a way as to promote meditation, and so any sort of haste that hinders recollection must clearly be avoided. During the Liturgy of the Word, it is also appropriate to include brief periods of silence, accommodated to the gathered assembly, in which, at the prompting of the Holy Spirit, the word of God may be grasped by the heart and a response through prayer may be prepared. It may be appropriate to observe such periods of silence, for example, before the Liturgy of the Word itself begins, after the first and second reading, and lastly at the conclusion of the homily.[60]
The Biblical Readings
57In the readings, the table of God’s word is prepared for the faithful, and the riches of the Bible are opened to them.[61] Hence, it is preferable to maintain the arrangement of the biblical readings, by which light is shed on the unity of both Testaments and of salvation history. Moreover, it is unlawful to substitute other, non-biblical texts for the readings and responsorial Psalm, which contain the word of God.[62]
58In the celebration of the Mass with a congregation, the readings are always proclaimed from the ambo.
59By tradition, the function of proclaiming the readings is ministerial, not presidential. The readings, therefore, should be proclaimed by a lector, and the Gospel by a deacon or, in his absence, a priest other than the celebrant. If, however, a deacon or another priest is not present, the priest celebrant himself should read the Gospel. Further, if another suitable lector is also not present, then the priest celebrant should also proclaim the other readings.
After each reading, whoever reads gives the acclamation, to which the gathered people reply, honoring the word of God that they have received in faith and with grateful hearts.
60The reading of the Gospel is the high point of the Liturgy of the Word. The Liturgy itself teaches that great reverence is to be shown to it by setting it off from the other readings with special marks of honor: whether on the part of the minister appointed to proclaim it, who prepares himself by a blessing or prayer; or on the part of the faithful, who stand as they listen to it being read and through their acclamations acknowledge and confess Christ present and speaking to them; or by the very marks of reverence that are given to the Book of the Gospels.
The Responsorial Psalm
61After the first reading comes the responsorial Psalm, which is an integral part of the Liturgy of the Word and holds great liturgical and pastoral importance, because it fosters meditation on the word of God.
The responsorial Psalm should correspond to each reading and should, as a rule, be taken from the Lectionary.
It is preferable that the responsorial Psalm be sung, at least as far as the people’s response is concerned. Hence, the psalmist, or the cantor of the Psalm, sings the verses of the Psalm from the ambo or another suitable place. The entire congregation remains seated and listens but, as a rule, takes part by singing the response, except when the Psalm is sung straight through without a response. In order, however, that the people may be able to sing the Psalm response more readily, texts of some responses and Psalms have been chosen for the various seasons of the year or for the various categories of Saints. These may be used in place of the text corresponding to the reading whenever the Psalm is sung. If the Psalm cannot be sung, then it should be recited in such a way that it is particularly suited to fostering meditation on the word of God.
In the dioceses of the United States of America, the following may also be sung in place of the Psalm assigned in the Lectionary for Mass: either the proper or seasonal antiphon and Psalm from the Lectionary, as found either in the Roman Gradual or Simple Gradual or in another musical setting; or an antiphon and Psalm from another collection of the psalms and antiphons, including psalms arranged in metrical form, providing that they have been approved by the United States Conference of Catholic Bishops or the diocesan Bishop. Songs or hymns may not be used in place of the responsorial Psalm.
The Acclamation Before the Gospel
62After the reading that immediately precedes the Gospel, the Alleluia or another chant indicated by the rubrics is sung, as required by the liturgical season. An acclamation of this kind constitutes a rite or act in itself, by which the assembly of the faithful welcomes and greets the Lord who is about to speak to it in the Gospel and professes its faith by means of the chant. It is sung by all while standing and is led by the choir or a cantor, being repeated if this is appropriate. The verse, however, is sung either by the choir or by the cantor.
The Alleluia is sung in every season other than Lent. The verses are taken from the Lectionary or the Gradual.
During Lent, in place of the Alleluia, the verse before the Gospel is sung, as indicated in the Lectionary. It is also permissible to sing another psalm or tract, as found in the Gradual.
63When there is only one reading before the Gospel:
During a season when the Alleluia is to be said, either the Alleluia Psalm or the responsorial Psalm followed by the Alleluia with its verse may be used;
During the season when the Alleluia is not to be said, either the psalm and the verse before the Gospel or the psalm alone may be used;
The Alleluia or verse before the Gospel may be omitted if they are not sung.
64The Sequence, which is optional except on Easter Sunday and on Pentecost Day, is sung before the Alleluia.
The Homily
65The homily is part of the Liturgy and is strongly recommended,[63] for it is necessary for the nurturing of the Christian life. It should be an exposition of some aspect of the readings from Sacred Scripture or of another text from the Ordinary or from the Proper of the Mass of the day and should take into account both the mystery being celebrated and the particular needs of the listeners.[64]
66The homily should ordinarily be given by the priest celebrant himself. He may entrust it to a concelebrating priest or occasionally, according to circumstances, to the deacon, but never to a lay person.[65] In particular cases and for a just cause, the homily may even be given by a Bishop or a priest who is present at the celebration but cannot concelebrate.
There is to be a homily on Sundays and holy days of obligation at all Masses that are celebrated with the participation of a congregation; it may not be omitted without a serious reason. It is recommended on other days, especially on the weekdays of Advent, Lent, and the Easter Season, as well as on other festive days and occasions when the people come to church in greater numbers.[66]
After the homily a brief period of silence is appropriately observed.
The Profession of Faith
67The purpose of the Symbolum or Profession of Faith, or Creed, is that the whole gathered people may respond to the word of God proclaimed in the readings taken from Sacred Scripture and explained in the homily and that they may also call to mind and confess the great mysteries of the faith by reciting the rule of faith in a formula approved for liturgical use, before these mysteries are celebrated in the Eucharist.
68The Creed is to be sung or said by the priest together with the people on Sundays and solemnities. It may be said also at particular celebrations of a more solemn character.
If it is sung, it is begun by the priest or, if this is appropriate, by a cantor or by the choir. It is sung, however, either by all together or by the people alternating with the choir.
If not sung, it is to be recited by all together or by two parts of the assembly responding one to the other.
The Prayer of the Faithful
69In the Prayer of the Faithful, the people respond in a certain way to the word of God which they have welcomed in faith and, exercising the office of their baptismal priesthood, offer prayers to God for the salvation of all. It is fitting that such a prayer be included, as a rule, in Masses celebrated with a congregation, so that petitions will be offered for the holy Church, for civil authorities, for those weighed down by various needs, for all men and women, and for the salvation of the whole world.[67]
70As a rule, the series of intentions is to be:
a. For the needs of the Church;
b. For public authorities and the salvation of the whole world;
c. For those burdened by any kind of difficulty;
d. For the local community.
Nevertheless, in a particular celebration, such as Confirmation, Marriage, or a Funeral, the series of intentions may reflect more closely the particular occasion.
71It is for the priest celebrant to direct this prayer from the chair. He himself begins it with a brief introduction, by which he invites the faithful to pray, and likewise he concludes it with a prayer. The intentions announced should be sober, be composed freely but prudently, and be succinct, and they should express the prayer of the entire community.
The intentions are announced from the ambo or from another suitable place, by the deacon or by a cantor, a lector, or one of the lay faithful.[68]
The people, however, stand and give expression to their prayer either by an invocation said together after each intention or by praying in silence.