The Solemn Evening Mass of the Lord's Supper commemorates the Institution of the Holy Eucharist and the ordination of the Apostles by our Lord at the Last Supper.
The Tabernacle on the main Altar is completely empty. However, to allow the Clergy and people to receive Holy Communion today and tomorrow, a ciborium (or ciboria) is placed on the Altar, containing hosts to be consecrated in this Mass.
Where there are not enough Clerics and Priests, Mass is celebrated according to the rite for sung Masses, and the incensation of the Altar is permitted as in Solemn Masses.
However, where there are Clerics, it is most fitting that they take part in the Solemn Evening Mass in the regular form of assistance in choir.
Therefore, everyone puts on his choral vestments: Priests add the stole; the Celebrant and Ministers wear the usual Mass vestments in white.
When everyone is ready, the Procession moves through the church to the Altar, while the Choir sings the Introit.
