After the conversion of Constantine, the progress of hymnody became closely connected with church controversies. There had been in Edessa, at the end of the 2nd or early in the 3rd century, a Gnostic writer of conspicuous ability, named Bardesanes, who was succeeded, as the head of his sect or school, by his son Harmonius. Both father and son wrote hymns, and set them to agreeable melodies, which acquired, and in the 4th century still retained, much local popularity. Ephraem Syrus, the first voluminous hymn-writer whose works remain to us, thinking that the same melodies might be made useful to the faith, if adapted to more orthodox words, composed to them a large number of hymns in the Syriac language, principally in tetrasyllabic, pentasyllable and heptasyllabic metres, divided into strophes of from 4 to 12, 16 and even 20 lines each. When a strophe contained five lines, the fifth was generally an "ephymnium," detached in sense, and consisting of a prayer, invocation, doxology or the like, to be sung antiphonally, either in full chorus or by a separate part of the choir. The _Syriac Chrestomathy_ of August Hahn (Leipzig, 1825), and the third volume of H. A. Daniel's _Thesaurus Hymnologicus_ (Leipzig, 1841-1856), contain specimens of these hymns. Some of them have been translated into (unmetrical) English by the Rev. Henry Burgess (_Select Metrical Hymns of Ephrem Syrus_, &c., 1853). A considerable number of those so translated are on subjects connected with death, resurrection, judgment, &c., and display not only Christian faith and hope, but much simplicity and tenderness of natural feeling. Theodoret speaks of the spiritual songs of Ephraem as very sweet and profitable, and as adding much, in his (Theodoret's) time, to the brightness of the commemorations of martyrs in the Syrian Church.