General Instruction of the Roman Missal: Chapter IV, The Different Forms of Celebrating Mass
112In the local Church, first place should certainly be given, because of its significance, to the Mass at which the Bishop presides, surrounded by his presbyterate, deacons, and lay ministers,[91] and in which the holy people of God participate fully and actively, for it is there that the preeminent expression of the Church is found.
At a Mass celebrated by the Bishop or at which he presides without celebrating the Eucharist, the norms found in the Caeremoniale Episcoporum should be observed.[92]
113Great importance should also be attached to a Mass celebrated with any community, but especially with the parish community, inasmuch as it represents the universal Church gathered at a given time and place. This is particularly true in the communal Sunday celebration.[93]
114Among those Masses celebrated by some communities, moreover, the conventual Mass, which is a part of the daily Office, or the community Mass, has a particular place. Although such Masses do not have a special form of celebration, it is nevertheless most proper that they be celebrated with singing, especially with the full participation of all members of the community, whether of religious or of canons. In these Masses, therefore, individuals should exercise the office proper to the Order or ministry they have received. It is appropriate, therefore, that all the priests who are not bound to celebrate individually for the pastoral benefit of the faithful concelebrate at the conventual or community Mass in so far as it is possible. In addition, all priests belonging to the community who are obliged, as a matter of duty, to celebrate individually for the pastoral benefit of the faithful may also on the same day concelebrate at the conventual or community Mass.[94] For it is preferable that priests who are present at a Eucharistic Celebration, unless excused for a good reason, should as a rule exercise the office proper to their Order and hence take part as concelebrants, wearing the sacred vestments. Otherwise, they wear their proper choir dress or a surplice over a cassock.
I. Mass with a Congregation
115By “Mass with a congregation” is meant a Mass celebrated with the participation of the faithful. It is moreover appropriate, whenever possible, and especially on Sundays and holy days of obligation, that the celebration of this Mass take place with singing and with a suitable number of ministers.[95] It may, however, also be celebrated without singing and with only one minister.
116If a deacon is present at any celebration of Mass, he should exercise his office. Furthermore, it is desirable that, as a rule, an acolyte, a lector, and a cantor should be there to assist the priest celebrant. In fact, the rite to be described below foresees a greater number of ministers.
The Articles to Be Prepared
117The altar is to be covered with at least one white cloth. In addition, on or next to the altar are to be placed candlesticks with lighted candles: at least two in any celebration, or even four or six, especially for a Sunday Mass or a holy day of obligation. If the diocesan Bishop celebrates, then seven candles should be used. Also on or close to the altar, there is to be a cross with a figure of Christ crucified. The candles and the cross adorned with a figure of Christ crucified may also be carried in the Entrance Procession. On the altar itself may be placed the Book of the Gospels, distinct from the book of other readings, unless it is carried in the Entrance Procession.
118The following are also to be prepared:
Next to the priest’s chair: the Missal and, as needed, a hymnal;
At the ambo: the Lectionary;
On the credence table: the chalice, a corporal, a purificator, and, if appropriate, the pall; the paten and, if needed, ciboria; bread for the Communion of the priest who presides, the deacon, the ministers, and the people; cruets containing the wine and the water, unless all of these are presented by the faithful in procession at the Offertory; the vessel of water to be blessed, if the asperges occurs; the Communion-plate for the Communion of the faithful; and whatever is needed for the washing of hands.
It is a praiseworthy practice to cover the chalice with a veil, which may be either the color of the day or white.
119In the sacristy, the sacred vestments (cf. nos. 337-341) for the priest, the deacon, and other ministers are to be prepared according to the various forms of celebration:
For the priest: the alb, the stole, and the chasuble;
For the deacon: the alb, the stole, and the dalmatic; the dalmatic may be omitted, however, either out of necessity or on account of a lesser degree of solemnity;
For the other ministers: albs or other lawfully approved attire.[96]
All who wear an alb should use a cincture and an amice unless, due to the form of the alb, they are not needed.
When there is an Entrance Procession, the following are also to be prepared: the Book of the Gospels; on Sundays and festive days, the thurible and the boat with incense, if incense is used; the cross to be carried in procession; and candlesticks with lighted candles.
A. Mass Without a Deacon
120Once the people have gathered, the priest and ministers, clad in the sacred vestments, go in procession to the altar in this order:
The thurifer carrying a thurible with burning incense, if incense is used;
The ministers who carry lighted candles, and between them an acolyte or other minister with the cross;
The acolytes and the other ministers;
A lector, who may carry the Book of the Gospels (though not the Lectionary), which should be slightly elevated;
The priest who is to celebrate the Mass.
If incense is used, before the procession begins, the priest puts some in the thurible and blesses it with the Sign of the Cross without saying anything.
121During the procession to the altar, the Entrance chant takes place (cf. nos. 47-48).
122On reaching the altar, the priest and ministers make a profound bow.
The cross adorned with a figure of Christ crucified and perhaps carried in procession may be placed next to the altar to serve as the altar cross, in which case it ought to be the only cross used; otherwise it is put away in a dignified place. In addition, the candlesticks are placed on the altar or near it. It is a praiseworthy practice that the Book of the Gospels be placed upon the altar.
123The priest goes up to the altar and venerates it with a kiss. Then, as the occasion suggests, he incenses the cross and the altar, walking around the latter.
124After doing these things, the priest goes to the chair. Once the Entrance chant is concluded, the priest and faithful, all standing, make the Sign of the Cross. The priest says, In nomine Patris et Filii et Spiritus Sancti (In the name of the Father, and of the Son, and of the Holy Spirit). The people answer, Amen.
Then, facing the people and extending his hands, the priest greets the people, using one of the formulas indicated. The priest himself or some other minister may also very briefly introduce the faithful to the Mass of the day.
125The Act of Penitence follows. Afterwards, the Kyrie is sung or said, in keeping with the rubrics (cf. no. 52).
126For celebrations where it is prescribed, the Gloria is either sung or said (cf. no. 53).
127The priest then invites the people to pray, saying, with hands joined, Oremus (Let us pray). All pray silently with the priest for a brief time. Then the priest, with hands extended, says the collect, at the end of which the people make the acclamation, Amen.
128After the collect, all sit. The priest may, very briefly, introduce the faithful to the Liturgy of the Word. Then the lector goes to the ambo and, from the Lectionary already placed there before Mass, proclaims the first reading, to which all listen. At the end, the lector says the acclamation, Verbum Domini (The word of the Lord), and all respond, Deo gratias (Thanks be to God).
Then, as appropriate, a few moments of silence may be observed so that all may meditate on what they have heard.
129Then the psalmist or even a lector proclaims the verses of the Psalm and the people sing or say the response as usual.
130If there is to be a second reading before the Gospel, the lector proclaims it from the ambo. All listen and at the end respond to the acclamation, as noted above (no. 128). Then, as appropriate, a few moments of silence may be observed.
131Afterwards, all rise, and the Alleluia or other chant is sung as required by the liturgical season (cf. nos. 62-64).
132During the singing of the Alleluia or other chant, if incense is used, the priest puts some into the thurible and blesses it. Then, with hands joined, he bows profoundly before the altar and quietly says, Munda cor meum (Almighty God, cleanse my heart).
133If the Book of the Gospels is on the altar, the priest then takes it and goes to the ambo, carrying the Book of the Gospels slightly elevated and preceded by the lay ministers, who may carry the thurible and the candles. Those present turn towards the ambo as a sign of special reverence to the Gospel of Christ.
134At the ambo, the priest opens the book and, with hands joined, says, Dominus vobiscum (The Lord be with you), and the people respond, Et cum spiritu tuo (And also with you). Then he says, Lectio sancti Evangelii (A reading from the holy Gospel), making the sign of the cross with his thumb on the book and on his forehead, mouth, and breast, which everyone else does as well. The people say the acclamation, Gloria tibi, Domine (Glory to you, Lord). The priest incenses the book, if incense is used (cf. nos. 276-277). Then he proclaims the Gospel and at the end says the acclamation, Verbum Domini (The Gospel of the Lord), to which all respond, Laus tibi, Christe (Praise to you, Lord Jesus Christ). The priest kisses the book, saying quietly, Per evangelica dicta (May the words of the Gospel).
135If no lector is present, the priest himself proclaims all the readings and the Psalm, standing at the ambo. If incense is used, remaining at the ambo he puts some into the thurible, blesses it, and, bowing profoundly, says, Munda cor meum (Almighty God, cleanse my heart).
136The priest, standing at the chair or at the ambo itself or, when appropriate, in another suitable place, gives the homily. When the homily is completed, a period of silence may be observed.
137The Creed is sung or recited by the priest together with the people (cf. no. 68) with everyone standing. At the words et incarnatus est (by the power of the Holy Spirit . . . and became man) all make a profound bow; but on the solemnities of the Annunciation and of the Nativity of the Lord, all genuflect.
138After the recitation of the Creed, the priest, standing at the chair with hands joined, by means of a brief introduction invites the faithful to participate in the Prayer of the Faithful. Then the cantor, the lector, or another person announces the intentions from the ambo or from some other suitable place while facing the people, who take their part by responding in supplication. After the intentions, the priest, with hands extended, concludes the petitions with a prayer.
139When the Prayer of the Faithful is completed, all sit, and the Offertory chant begins (cf. no. 74).
An acolyte or other lay minister arranges the corporal, the purificator, the chalice, the pall, and the Missal upon the altar.
140It is appropriate for the faithful’s participation to be expressed by an offering, whether of the bread and wine for the celebration of the Eucharist or of other gifts for the relief of the needs of the Church and of the poor.
The offerings of the faithful are received by the priest, assisted by the acolyte or other minister. The bread and wine for the Eucharist are carried to the celebrant, who places them upon the altar, while other gifts are put in another appropriate place (cf. no. 73).
141At the altar the priest accepts the paten with the bread. With both hands he holds it slightly raised above the altar and says quietly, Benedictus es, Domine (Blessed are you, Lord). Then he places the paten with the bread on the corporal.
142After this, as the minister presents the cruets, the priest stands at the side of the altar and pours wine and a little water into the chalice, saying quietly, Per huius aquae (By the mystery of this water). He returns to the middle of the altar, takes the chalice with both hands, raises it a little, and says quietly, Benedictus es, Domine (Blessed are you, Lord). Then he places the chalice on the corporal and covers it with a pall, as appropriate.
If, however, there is no Offertory chant and the organ is not played, in the presentation of the bread and wine the priest may say the formulas of blessing aloud, to which the people make the acclamation, Benedictus Deus in saecula (Blessed be God for ever).
143After placing the chalice upon the altar, the priest bows profoundly and says quietly, In spiritu humilitatis (Lord God, we ask you to receive us).
144If incense is used, the priest then puts some in the thurible, blesses it without saying anything, and incenses the offerings, the cross, and the altar. A minister, while standing at the side of the altar, incenses the priest and then the people.