The use of an unchanging language like Latin and some Oriental languages is intended to he a safeguard against new meanings that grow into words in the use of living tongues. It is not necessary, on the theory here explained, that the words should be understood or even heard in de tail by the congregation any more than it was necessary for the Jews to enter the sanctuary where the sacrifice was being offered. They un derstand that they are taking part in the supreme act of worship though even the assistant at the priest's side may not be able to hear the words of consecration.
For the vestments used in the mass, see COS TUME, ECCLESIASTICAL; and for the early devel opment of liturgical structure, see LITURGY. The mass is divided into two main parts, known from ancient analogy as miss(' eatechumenbruni and miss(' fidthien, the latter o• more sacred part having been originally that from which the un baptized were excluded. ( See DISCI PLI NA ARCANI.) A similar distinction. though not identical, is made between the Pro-Anaphora and Anaphora of the Greek liturgies. The first consists of the celebrant's preparation at the font of the altar, introit, Kyrie eleison„ Gloria, collect, epistle and gospel, and creed. The second begins with the offertory or oblation of the elements: the preface leads up to the Sanctus, and then follow the canon o• practically unvarying central portion of the mass (including the consecration) and its accompanying prayers. the communion, and the post-communion: the congregation is dismissed with the ancient formula lie missa est, from which the mass derives its name (Lat. missa).
See the articles on all the more important parts of the service named above.
The musical history connected with the mass is of considerable importance, as the early devel opment of polyphonic music was almost exclusive ly along the lines of sacred use. Originally the whole service, when sung, was set to plain chant (q.v.) : hut later the Kyrie, Gloria, Credo, Sane tax, and .1gnu•s Del were detached and set to new music, these numbers constituting what is called a mass in the musical sense. The masses of the composers of the Gallo-Belgic school of the fifteenth century had become so emnplicated and overloaded with contrapuntal tricks that a desire for a simple and more dignified style was created. Palestrina inaugurated the new epoch, in writing distinguished by grandeur and maj esty; his compositions were usually for four to eight. voices. The great masters of the seven teenth and eighteenth centuries wrote masses for eight. twelve, sixteen. twenty-four, and sotin.t inies even inure voices. All these works were written a cappella. without instrumental accompaniment. The development of instrumental music suggested new coinbillat ions, and the missa so/cm nis of Bach and Beethoven thus grew up. Gonnod, Silas, and \\ idor have given notable examples of this style in more recent times. See SACRED 1\ !USW.
Consult: Gihr, Das lye cssopfer dogma isch, urgisch and a see I isch crk 101 (5th ed., Freiburg, 1892; Eng. trans.. Saint Louis, 1002) ; and many of the books referred to under LORD'S SUPPER.