Gregory the Great, two centuries later, carried forward the work of Ambrose. He added four more scales or modes to the Ambrosian system, thus giving to the repertory of church music more definiteness and variety. The music that developed during the papacy of Gregory came to be known as Gregorian Chant, or plainsong, or plainchant. It is “plain” because unadorned, unharmonized and unmeasured. Its rhythm is the free rhythm of speech, the beats falling irregularly. The Gregorian Chant remained the music of the church for a thousand years and forms the basis of all Roman Catholic music today. Some of these chants were adapted by Luther for congregational singing, and set to words in the vernacular of the people. A few of the tunes, usually in a form scarcely recognizable from the original, are used today in Protestant hymnals, as for instance, the tune “Hamburg.” Some of the music in the Amish church services is traceable to the Gregorian Chant. The singing in the medieval church was liturgical in character and confined to the clergy and trained choirs. This was its weakness. The laity was not expected to sing, neither were they able to do so. Congregational singing, so important in our worship today, had for centuries been unknown in the Roman Catholic Church. Reform was inevitable and it came in due time. While only remnants of the music survive, many hymns from the Western Church have been translated from the Latin and a few choice ones have found their way into the _Hymnary_. Latin Hymns in the Hymnary Prudentius, 348-c. 413, “Bethlehem, of noblest cities” (88) Gregory the Great, 540-604, “Father, we praise Thee” (24) Anonymous, 6th or 7th century, “Christ is made the sure” (277) “Joy dawned again on Easterday” (415) Theodulph of Orleans, 9th century, “All glory, laud, and honor” (100) Bernard of Clairvaux, 1091-1153, “Jesus the very thought” (155) “O sacred Head, now wounded” (539) Bernard of Cluny, 12th century, “Jerusalem, the golden” (262-3) Anonymous, 12th century, “O come, O come, Emmanuel” (67) Savonarola, 1452-98 (Italian), “Jesus, Refuge of the weary” (536) Anonymous, 17th-18th centuries, “O come, all ye faithful” (80) “The year is gone beyond recall” (382) 5. Hymns of the Bohemian Brethren. The followers of John Hus who came to be known as the Bohemian Brethren, and later as the Moravians, were the first Protestant group to introduce congregational singing into their worship. They also published the first Protestant hymnbooks, one in 1501 and another in 1505, containing 89 and 400 hymns, respectively, in their native Bohemian tongue. Their efforts to introduce congregational singing were sternly opposed by the Roman hierarchy. The Council of Constance condemned Hus to be burned at the stake and warned his successor, Jacob of Misi, to cease the singing of hymns in the churches. It decreed: