It is remarkable that the Anglicans are singing this and quite remarkably, which isn't remarkable!
Many criticize the Sistine Chapel Choir for not being as good as they should be. Well, Westminster Abbey Choir (Church of England!) sang the Mass this morning for the Solemnity of Saints Peter and Paul, singing Latin chant and some Anglican style music putting to rest the notion that the Sistine choir is almost as good. It isn't!
There is no reason on God's good earth that the Vatican cannot have a top rated choir, it is improving and for them to hear the Westminster Abbey choir sing along with them and separately will certainly inspire excellence in style for the Sistine Choir. Ecumenism is good!
The Pallium was imposed on the new Metropolitans as a prelude to the Mass. As soon as the Pallium ceremony concluded, the Mass began with the Sign of the Cross, greeting, penitential act and Kyrie and the Gloria by the Westminster Abbey Choir. The pope should have worn cope for this prelude and changed into chasuble for the Mass, oh well.
As is the custom in Rome for concelebrated Masses which should become the norm in the USA, the concelebrants do not receive the Sacred Host during the Agnus Dei as is the custom here, but rather they approach the altar as others are receiving Holy Communion, take the host from a ciborium and intinct (dip)the Most Sacred Host into a chalice of the Most Precious Blood. It is very sanitary to say the least and quite acceptable!
At the end of the Mass, the Holy Father greeted the choir directors of the Westminster Abbey Choir which sang directly behind the altar, then the Holy Father knelt at the "confessio" of Saint Peter and the choir sang marvelously "Tu Es Petrus!" It doesn't get any more ecumenical than that!