What is the Structure of the Mass in the Extraordinary Form?
The first part of the Mass is a kind of introductory service, made up of chants, prayers and lessons (i.e. readings from Holy Scripture) — namely, the Introit, the Kyrie, the Collect, the Epistle or Lesson, and the Gospel. On certain days the Gloria and the Nicene Creed are added. This first part of the Mass is called the Mass of the Catechumens, while the remaining part is called the Mass of the Faithful. These names have their origin in the discipline of the early Church. In the first ages of Christianity, persons desiring to become Christians were obliged to undergo a course of instructions preparatory to baptism. They were called “catechumens,” a Greek word meaning “one whose is being instructed.” Catechumens, not yet fully initiated in the teachings and practices of Christianity, were customarily dismissed before the Offertory. Likewise public sinners who had not yet been absolved were ordered to leave the church before the Offertory. The Sacrifice of the Mass was considered too
