In reading through the Introduction to the GR and the OCM, it seems that the structure envisioned for the Introit is: Antiphon - Verse - Antiphon - (repeat verses and antiphon as needed) - GP after the penultimate antiphon- Antiphon.
In the Liber Usualis, the structure given is: Antiphon - Verse - (repeat verses and antiphon as needed) - GP after the last verse- Antiphon.
Am I reading this correctly, then, that the Antiphon is to be repeated before the GP in the OF but not in the EF?
We have also sung, ANT., verse, ANT., G.P., then ANT. We find that for most Masses you only have time for at most 2 verses. This includes the Salve Sancta Parens and Terribilis, that are very short Introits.
The change is because of a change of function. Traditionally the choir sings the Introit and Kyrie starting when the celebrant arrives at the sanctuary. The priest says the prayers at the foot of the altar, incenses the altar, and reads the Introit and Kyrie, and then probably has to wait while the choir finishes. In the OF the Introit starts when the entrance procession leaves the sacristy, and continues during the incensing of the altar, which if done is more elaborate than in the EF. Depending on the length of the entrance procession, the singing may be longer, or shorter, so there is considerable flexibilty built into the structure.
To participate in the discussions on Catholic church music, sign in or register as a forum member, The forum is a project of the Church Music Association of America.