Unison liturgical chant of the Byzantine Empire to the 16th century.
It probably derived principally from Hebrew and Syrian Christian liturgies. A system of eight mode s, very similar to the eight Greek modes, was used for psalms and hymns, each mode (or echos ) consisting primarily of a few melodic formulas. The principal hymn genres were the troparion (one or more stanzas of poetic prose), the kontakion (a metrical sermon), and the kanon (a complexly ordered set of hymn types). See also Gregorian chant .