Introit

Introit, in the Roman Catholic Church, an anthem sung at the beginning of the mass, immediately after the Confiteor, and when the priest has ascended to the altar. It consists of an antiphon, Gloria Patri, and usually part of a psalm; but other passages of Scripture are used, while a few introits in the present Missal are taken from uninspired writers, and one (Whitsunday) is from 2d Esdras. The introduction of introits is ascribed to Gregory the Great (595), or perhaps to Celestine (423). In the first prayer-book of Edward VI. an introit is prefixed to each collect, consisting of a psalm to be sung after the opening prayer in the communion office.