Having received from the Holy Father the mandate to take care of and animate the liturgical life of Saint Peter’s Basilica, I would like to propose some considerations based on the communiqué of the Secretariat of State of 12 March 2021, which I hope will be useful in understanding the guidelines outlined and in choosing how and when to celebrate the Eucharist in the first part of the morning.
The communiqué of the Secretariat of State gives some provisions regarding the celebration of Holy Masses in Saint Peter’s Basilica, with the intention of ensuring that they “take place in an atmosphere of recollection and liturgical decorum”. The indications refer to a precise context, namely the organisation of liturgical actions in the period of time between 7 and 9 am.
In essence, they are inspired by two principles:
a. the ordering of the celebrations from the point of view of their temporal scansion and quality;
b. the accommodation and integration of the particular and legitimate wishes of the faithful, as far as possible.
Indeed, the content of the statements proposed by the Secretariat of State may be summarised as follows:
a. between 7 a.m. and 9 a.m. priests may concelebrate at one of the hourly Masses in the established places; the liturgical animation shall include the assistance of ministrants;
b. b. exceptions are admitted with regard to the place of celebration - on the occasion of the memory of a saint whose remains are kept in the Basilica - and to the simultaneous celebration of certain celebrations for groups of pilgrims or in the extraordinary form of the Roman Rite.
For the sake of ease of reading, these notes are structured in accordance with the two points mentioned above.
A Concelebrations from 7 to 9 a.m.
The way in which the morning celebrations are organised in the communiqué of the Secretariat of State constitutes an opportunity to recall the meaning and value of Eucharistic concelebration which, as the Fathers recalled at the last Council, is part of the Tradition of the Church: “Concelebration, whereby the unity of the priesthood is appropriately manifested, has remained in use to this day in the Church both in the east and in the west” (Sacrosanctum concilium, 57). This is why the Second Vatican Council, in its Constitution on the Sacred Liturgy, extended the right of presbyters to concelebrate, and a number of magisterial documents subsequently clarified the rules.  In this regard, it may be useful to recall some cases in which the Magisterium recommends concelebration, such as at the main Mass in a church or at Masses on the occasion of meetings of priests, whether secular or religious, whatever their character (cf. SC57; General Instruction of the Roman Missal 199).
On the other hand, the very nature of the celebration is clearly defined in Sacrosanctum concilim, where it is stated, in the Norms drawn from the hierarchic and communal nature of the Liturgy, that “Liturgical services are not private functions, but are celebrations of the Church, which is the ‘sacrament of unity’, namely, the holy people united and ordered under their bishops. Therefore liturgical services pertain to the whole body of the Church; they manifest it and have effects upon it. … Whenever rites, according to their specific nature, make provision for communal celebration involving the presence and active participation of the faithful, this way of celebrating them is to be preferred, so far as possible, to a celebration that is individual and quasi-private. This applies with especial force to the celebration of Mass and the administration of the sacraments, even though every Mass has of itself a public and social nature (SC 26-27).
Therefore, the assembly gathered for the Eucharist fully manifests the mystery of the Church, the living Body of Christ. This is recalled by Lumen Gentium2] when it refers to the common priesthood exercised in the sacraments, and it is also clearly recalled by the Catechism of the Catholic Church, which affirms that it is the whole community, the Body of Christ united to its Head, that celebrates (1140). From this perspective, one understands how the greatest fruit of the Eucharist is drawn from participation in the same action, because it better expresses the mystery that is celebrated. 
Clearly, all those who compose the assembly gathered for the Eucharist participate in the one sacrifice and priesthood of Christ, each according to his or her own state and condition of life: Bishop, presbyter, deacon, baptised, married, religious. In the Mass concelebrated by several priests there is no diminution of the value and fruits of the Eucharistic sacrifice, but rather a full exaltation of them.
A first element for discernment, in our context, is therefore the following: when possible, it is more than opportune for priests to concelebrate, given the fact that there is a regular alternation of presidency for the concelebrations that ordinarily take place in Saint Peter’s Basilica. The same is also true for individual faithful and groups, invited to participate in the same Mass so that it may be an expression of fraternity and not of particularisms that do not reflect the sense of ecclesial communion manifested by the Eucharistic celebration.
The Magisterium teaches that exceptions are made to the situations in which concelebration is recommended in those cases in which the benefit of the faithful does not require it, or it is advised otherwise..
In this sense, the importance of the understanding of language in the liturgy in relation to the love (cf.1 Cor 14) and pastoral value that the celebration of the Eucharist may have for a group of pilgrims, in accordance with the existing Rites of the Catholic Church, should not be underestimated.
In addition to these considerations, there are some elements of the reality of the Basilica that must be taken into account:
-the dimensions of Saint Peter’s Basilica and its architecture make it possible to meet the different needs of those who wish to celebrate the Eucharist in groups without clashing with the concelebration taking place in the main liturgical places;
-Saint Peter’s Basilica is characterised by the Petrine ministry of unity, mercy and orthodoxy of the faith and welcomes pilgrims from all over the world;
-in the time slot between 7 a.m. and 9 a.m., attendance at the Basilica is numerically limited;
-for celebrations with the Missale Romanum of 1962, everything possible must be done to fulfil the wishes of the faithful and priests, as laid down in the Motu Proprio Summorum Pontificum.
Moreover, without in any way detracting from the legitimacy of the celebration of Mass by individual priests even when the faithful are unable to attend,  it is necessary to recognise the direct character of the norm that forbids the celebration “in an individual manner [...] at the same time as concelebration is taking place in the same church or oratory”. 
For this reason, I have already given instructions to ensure that requests from groups with special and legitimate needs to celebrate during the 7-9 a.m. period will be granted. Requests for individual celebrations can also be discerned on a case-by-case basis, without prejudice to the principle that everything should take place in an atmosphere of recollection and decorum, and taking care to ensure that what is exceptional does not become ordinary, distorting the intentions and meaning of the Magisterium.
In this way, I am confident that the path that has been embarked upon may encourage every priest and every member of the faithful to experience celebrations in Saint Peter’s Basilica in a way that is ever more ordered to goodness, beauty and truth.
Vatican City, 22 June 2021.
Mauro Cardinal Gambetti
Archpriest of the Papal Basilica of Saint Peter
 See, for example: General Instruction on the Roman Missal;Declaration on Concelebration, of the Sacred Congregation for Divine Worship, 7 August 1972;CIC902.
“Taking part in the Eucharistic sacrifice, which is the fount and apex of the whole Christian life, [the faithful] offer the Divine Victim to God, and offer themselves along with it. Thus both by reason of the offering and through Holy Communion all take part in this liturgical service, not indeed all in the same way but each in that way which is proper to himself. Strengthened in Holy Communion by the Body of Christ, they then manifest in a concrete way that unity of the people of God which is suitably signified and wondrously brought about by this most august sacrament” (Lumen gentium, 11).
 In his work Sacrifice, sacrament and priesthood in the development of the Church (Proclaimers of the Word and Servants of Your Joy, LEV 2013) Joseph Ratzinger states: “The true place of the existence of the Church is not some bureaucracy, not even the activity of a group that claims to be the "base", but the "assembly". It is the Church in action [...]. More precisely: the content of the assembly is the reception of the word of God, which culminates in the memorial of Jesus' death, in a memorial that realises his presence and signifies mission. It follows from this that every assembly is entirely Church, since the body of the Lord cannot but be all and the word of God in turn cannot but be all. At the same time, however, it follows that the individual assembly, the individual community, remains Church only if it is in the whole, in unity with the others” (p.82).
 On the goodness of the concelebration of the Eucharist, what is indicated for Shrines in no. 268 of the Directory of popular piety and liturgy. Principals and guidelines, Vatican City 2002, is enlightening.
 Cf.SC57; General Instruction of the Roman Missal 199;CIC902.
 When there is no possibility for the faithful to participate, the daily celebration of the Mass is nevertheless recommended for priests. The Council teaches this in the decree Presbyterorum Ordinis: "In the mystery of the Eucharistic sacrifice, in which priests fulfil their greatest task, the work of our redemption is being constantly carried on; and hence the daily celebration of Mass is strongly urged, since even if there cannot be present a number of the faithful, it is still an act of Christ and of the Church " (13).