If the day was one of the solemn feasts, upon which the abbot celebrated in pontificals, he was vested by the sacred ministers before the altar in the sacristy, whilst Tierce was being sung in the choir. At the conclusion of the Hour he entered with due solemnity, being met at the door of the choir by the prior and others, and he took his seat upon a throne erected before his stall in the upper part of the choir until the procession was formed. The abbot only celebrated at the High Altar on these great feasts; and never except with full pontifical ceremonies, if he had the right to use pontificalia at all.
In most monasteries several times a year--four or more, according to custom and circumstances--there were exceptionally solemn processions with relics and banners. On these occasions every care was taken to make the religious pageants worthy of the best traditions of the monastery. Such processions would be preceded by the vergers of the church with their maces of office; and the community, all vested in copes, walked in couples with some four feet between them and between the next couple. Every here and there a single individual walked in the middle carrying an appropriate banner; and at intervals the great shrines, which were the special pride of the house, or the chief notable relics, were borne by the requisite number of religious clad in sacred vestments. At the close of the procession came the abbot in full pontificalia, assisted by his sacred ministers. Finally, following the church servers, walked the _janitor_ of the church, or "door-keeper," "who," according to one Custumal, "was to raise his rod well above his head, to warn the people who pressed on after the procession, to stand farther away."
These were the ceremonies preliminary to the High Mass on Sundays and on the greater festivals. Ordinarily speaking, the conventual High Mass would begin either directly after Tierce, or if that Hour had been already recited at the time of the early Mass, immediately the community had entered the choir, and the cessation of the bell-ringing had given notice that the prior was in his place. The two juniors appointed by the cantor had meanwhile taken the graduals and psalters from the presses in the choir, and had distributed them to the seniors, juniors, and novices according to their needs. The cantor of the week, also, had by this time put on his cope, had chosen a book, and had taken his stand at the lectern to be ready to lead the singing. The High Mass then commenced and went on as usual till after the Blessing. At the Offertory the prior or some of the seniors brought the oblations to the altar and gave them to the celebrant. On Sundays, after the Blessing, the hebdomadarian priest gave the usual benediction to the weekly reader, who had come forward from his place in choir to the steps of the presbytery to receive it. The Gospel of St. John was said after the priests and the ministers had reached the sacristy and were standing before the altar there, whilst the community were leaving the choir for the next conventual duty, or were unvesting, if they had that day worn copes or albs.