When early Christian music finally freed itself from the influence of Pagan models in the interest of its own internal necessities, it opened the way for the first time in history for the development of a purely vocal art, dispensing with the assistance of the instruments that formed such an essential part of the musical practices allied with Pagan religious rites and ceremonies. For the first fifteen centuries of the Christian era almost the only art-music was that which was cultivated by and for the church, and since the church during this period persistently frowned upon the use of instruments, the history of the music of the period is the history of choral music. But while in Italy the use of instruments was rigidly forbidden and any deviation from prescribed practices was a punishable offense, greater difficulty was experienced in enforcing this church law in those countries of Europe, now known as France, Germany, and England, which had more recently been won to the standard of Christianity by the militant missionaries of Rome, but which still retained a rugged independence that clung tenaciously to many local customs. In some of these localities instruments were freely used and in the monastery of St. Gall in Switzerland festival occasions were graced by a band of harps, flutes, cymbals, a seven-stringed psaltery, and an organ. Notwithstanding a few noteworthy exceptions, the music of the Roman Church can be characterized as pure vocal music until near the end of the sixteenth century at least. And when instruments were occasionally used--the organ more and more toward the end of the sixteenth century--it was for the purpose of doubling the voice-parts in order to gain greater sonority. After the office of song was restricted to specially trained clericals, thus bringing music within the domain of culture and laying the foundation for its development as an art, the first name of importance among those who strove to bring order and increased effectiveness into the chaotic conditions of liturgical music was St. Ambrose, Bishop of Milan (340?-397). Much that was attributed to him until a few decades ago has been proved to be apocryphal and legendary. We may with much certainty, however, affirm that his enthusiastic interest in the music of the liturgy resulted (1) in carefully sifting the material that had been gradually accumulating, and (2) in bringing into the ritual of the Western church from the Eastern three elements of great value to its further development--antiphonal singing of psalms by two alternating choirs, responsorial singing, and Greek hymnody. His great interest in the last-named field led him not only to translate many of the finest Greek hymns into Latin, but inspired him to write new Latin hymns to be sung, probably to simple melodies, after the Greek fashion. Among the hymns (about ten in number) from his own pen may be named _Veni Redemptor Gentium_ and _Eterna Christi Munera_ (‘Hymnal Noted,’ Nos. 12 and 36).