 Arians, Marcionites, Manichees, Bardaisanites and various gnostic sects proclaimed themselves as the true church.In this confusion, Ephrem wrote a great number of hymns defending Nicene orthodoxy.A later Syriac writer, Jacob of Serugh, wrote that Ephrem rehearsed all-female choirs to sing his hymns set to Syriac folk tunes in the forum of Edessa.