Among the parts assigned to the priest, the foremost is the Eucharistic Prayer, which is the high point of the entire celebration. Next are the orations: that is to say, the collect, the prayer over the offerings, and the prayer after Communion. These prayers are addressed to God in the name of the entire holy people and all present, by the priest who presides over the assembly in the person of Christ.43Cf. Second Vatican Ecumenical Council, Constitution on the Sacred Liturgy, Sacrosanctum Concilium, no. 33. It is with good reason, therefore, that they are called the “presidential prayers.”
It is also up to the priest, in the exercise of his office of presiding over the gathered assembly, to offer certain explanations that are foreseen in the rite itself. Where it is indicated in the rubrics, the celebrant is permitted to adapt them somewhat in order that they respond to the understanding of those participating. However, he should always take care to keep to the sense of the text given in the Missal and to express it succinctly. The presiding priest is also to direct the word of God and to impart the final blessing. In addition, he may give the faithful a very brief introduction to the Mass of the day (after the initial Greeting and before the Act of Penitence), to the Liturgy of the Word (before the readings), and to the Eucharistic Prayer (before the Preface), though never during the Eucharistic Prayer itself; he may also make concluding comments to the entire sacred action before the dismissal.
The nature of the “presidential” texts demands that they be spoken in a loud and clear voice and that everyone listen with attention.44Cf. Sacred Congregation of Rites, Instruction Musicam sacram, On music in the Liturgy, 5 March 1967 , no. 14: AAS 59 (1967), p. 304. Thus, while the priest is speaking these texts, there should be no other prayers or singing, and the organ or other musical instruments should be silent.
The priest, in fact, as the one who presides, prays in the name of the Church and of the assembled community; but at times he prays only in his own name, asking that he may exercise his ministry with greater attention and devotion. Prayers of this kind, which occur before the reading of the Gospel, at the Preparation of the Gifts, and also before and after the Communion of the priest, are said quietly.