The Mass

In the beginning, the whole communion service was called Mass. For it followed the general service, and because it was considered something mysterious, as it is, not only the non-Christians present, but also the catechumens and new converts, were not yet allowed to take part in it, so that the sacristan called out before the service began: Ite missa est ecclessia - "Go, the assembly is dismissed!"
Gregory the Great formed the customs of the Mass. Because the Mass is at the same time a symbolic representation of the Passion of Christ, the actions of the priest and every part of his service must allude to the special circumstances of the Passion, whereby the various positions and movements have their own meaning. It is divided into three parts: 1. the Offertory, the elevation and veneration of the consecrated host, usually in a very costly capsule, the monstrance, which elevation appeared in the fourth century, and also that chant which is intoned by the choir under organ accompaniment during the mass, when the people go to the sacrifice. 2. the consecration or consecration of the host and wine, which is offered for the living and the dead, and then partaken of by the priest. 3. the sumtion, or partaking of the bread and wine. When music is connected with the Mass, it is usually called High Mass. Music which consists in a composition of the words of the Kyrie Eleison, Gloria, Nicene Symbolum, the Sanctus with the Benedictus, and the Agnusdei, is also called a Mass by the musicians. According to the various degrees of solemnity and the several or few persons who participate, it is divided into high or great or low masses. The former is sung by the choristers and said by a priest; it is even more solemn when said by the bishop. The most solemn is the papal. Masses also differ according to the feasts on which they are celebrated, e.g. the Mass of the Saints, and according to the occasions on which they are celebrated. Thus the holy mass of Christ is said at a solemn election or assembly of the clergy, and at the same the chant, Veni creator Spiritis - "Come God Creator Holy Spirit," is intoned as a supplication for illumination . A special kind of masses are the masses for souls, which have the special purpose of snatching the souls of the deceased from purgatory, or of relieving the torments of the same. Masses for the souls are said for the deceased a few weeks after the funeral and are called Requiems. Requiem is a solemn, musical mass for the souls, beginning with the words, Requiem asternam dona eis, etc.-"Grant them an eternal rest."
Before the priest ascends the altar, he confesses his sins to God before it, whereupon he ascends the altar, folds his hands, unfolds them, and folds them again to indicate his desire for God's grace, and kisses the altar to prove his love. Now the Mass begins with the Introit, the Kyrie Eleison, and the Glory, the latter, however, being omitted at funeral Masses and during the Passiontide. The priest then turns to the people with the greeting, Dominus vobiscum-"The Lord be with you!" and is followed by the Collect, Epistle, Gospel, and Faith. The Epistle is sung or read on the right, the Gospel on the left, and the Faith is sung or read in the center of the altar. If the priest sings or reads the Gospel, the people stand and signify themselves with the cross. This is followed by the offering. The priest raises the bread and chalice on high and calls out, Orate fratres - "Pray, brothers!" The priest pronounces this holy three times; then the bell is rung and a candle is lighted to encourage devotion, while the priest holds his hands over the offerings as a sign that he places on them his and the people's sins. Then follows the Consecration, wherewith the wall begins, and raises the Host aloft, the people beating their breasts in token of their repentance for their sins. He then takes the Host in his hands, breaks it into three parts, and drops one part of it into the chalice, whereupon he prays the Agnes dei, beating his breast three times. This prayer was ordered by Pope Sergius I in the year 688. Various little prayers are also said by the priest, such as Domine non sum dignus, etc.—"O Lord, I am not worthy that thou shouldst go under my feet, but say but one word, and my soul shall be healed," — upon which the priest administers Communion to himself. The use of the bell is introduced as a sensual sign that the congregation should worship the transformed body of the Lord when the priest raises it on high. After the enjoyment has taken place, the priest turns again to the people and says: Ite missa est ecclsesia - "Go, the congregation is dismissed". With the blessing, the congregation is dismissed and finally the priest, facing the altar, reads the first chapter of the Gospel of St. John as a sign of adoration of the Incarnate Word.