The mass, or missa (“missa est,” the congregation is dismissed), has been used, in part, at any rate, from the very earliest times, and has been sung to most impressive and solemn music. St. Ambrose and St. Gregory appear as the earliest compilators of the mass music. When counterpoint was invented, Church composers clothed the early plain-song tunes with its artistic embroideries, and polyphonic masses arose, gradually brought by the great schools of the sixteenth century to such a pitch of excellence that they have never since been equalled. The mass then consisted, as it does now, of six movements, viz., the Kyrie, Gloria, Credo, Sanctus, Benedictus, and Agnus Dei. The masses were named after the plain-song melody upon which they were developed; but occasionally the melody used was a profane one, so that a mass would be named after its secular melody, as, for instance, “L’homme armée,” an old French lovesong! and the masses founded upon an original theme were rare, and known as “Missa _sine nomine_.” The tenor Du Fay, already named in connection with the motett, wrote many of a very devotional but unmelodious character. At the end of the fifteenth century Josquin des Prés, also mentioned previously, wrote many masses, in which, strange to say, a great want of reverence is most evident from time to time. A purer style will be found later on in the masses of Goudimel, Morales, and notably in those of Festa. But about this period the abuse spoken of in treating of the motett had crept into the mass, and the device was to give different sets of words to each singer! Even Morales is guilty of this, mixing up, as he does, the text of the Liturgy and an Ave Maria. Devotional feeling was sacrificed to a desire to puzzle, and masses were esteemed according to the difficulty of the solution of the canons employed in them. At the Council of Trent (1562) these abuses were condemned, and polyphonic music would have been forbidden a place in the Church, but for one great, earnest man, and that man was Palestrina. His now celebrated “Missa Papæ Marcelli” decided the fate and fixed the style of Church music. In it he demonstrated that these intricacies and learned forms might be well and devotionally used as a means to the highest end, but not as a substitute for that great end itself. He wrote nearly a hundred masses, and greatly influenced the future of Church music. William Byrd wrote a mass for five voices of great interest. Vittoria, Orlando di Lasso, Gabrieli—each represented their different schools and advanced their Church music on Palestrina’s great model.