ROME — Reaffirming the principles that led the Vatican to severely limit private celebrations of Mass in St. Peter’s Basilica in the early morning, Cardinal Mauro Gambetti, the new archpriest of the basilica, said exceptions would be made for “groups with particular and legitimate needs.”

In addition, requests by priests to celebrate alone, without a congregation, “may also be discerned from time to time, without prejudice to the principle that everything should take place in an atmosphere of recollection and decorum and with vigilance, so that what is exceptional does not become ordinary, distorting the intentions and the sense of the magisterium,” the cardinal wrote in a note released by the Vatican press office June 22.

A letter dated March 12 and initialed by Archbishop Edgar Peña Parra, substitute secretary for general affairs in the Vatican Secretariat of State, had said that beginning March 22, “individual celebrations (of the Mass) are suppressed,” and priests wanting to celebrate in the basilica in the early morning would be invited to join a concelebrated liturgy.

Peña’s letter also severely limited celebrations of the Mass according to the “extraordinary form,” sometimes referred to as the Tridentine rite, by saying priests who wanted to use the rite could do so only in the Clementine Chapel in the grotto under the basilica at 7, 7:30, 8 and 9 a.m. Because concelebration is not foreseen by the rite, that meant that only four priests could celebrate the old Mass each day in the basilica.

Gambetti’s note, however, said that “everything possible must be done to fulfill the wishes of the faithful and priests as foreseen by the motu proprio ‘Summorum Pontificum,’” Pope Benedict XVI’s 2007 document allowing wider celebration of the old rite.

The restrictions instituted by the Secretariat of State were in line with the Code of Canon Law, which says priests “are completely free to celebrate the Eucharist individually, however, but not while a concelebration is taking place in the same church or oratory.” Multiple individual Masses were being celebrated simultaneously at different altars throughout the basilica.

Gambetti’s note said the March instruction highlighted “the meaning and value of eucharistic concelebration” as explained by the Second Vatican Council.

The very nature of the Mass is communal, he said, pointing to the council’s Constitution on the Sacred Liturgy, which said, “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; but they concern the individual members of the church in different ways, according to their differing rank, office, and actual participation.

“It is to be stressed that 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,” the Vatican II document continued.

Since the Mass is a celebration of the unity of the body of Christ, the church, he said, “the greatest fruit of the Eucharist is drawn from participation in the same action, because it better expresses the mystery being celebrated.”

And, perhaps replying to some commentators who thought that somehow more Masses would create more grace, Gambetti wrote, “In the Mass concelebrated by several presbyters there is no diminution of the value and fruits of the eucharistic sacrifice, but rather a full exaltation of them.”

He said, however, that there are times when the faithful would benefit from a Mass in their own language, which is why exceptions are made for pilgrim groups traveling with a priest.