Byzantine music (Greek: Βυζαντινή μουσική, romanized: Vyzantini mousiki) originally consisted of the songs and hymns composed for the courtly and religious ceremonial of the Byzantine Empire and continued, after the fall of Constantinople in 1453, in the traditions of the sung Byzantine chant of Eastern Orthodox liturgy. The ecclesiastical forms of Byzantine music are the best known forms today, because different Orthodox traditions still identify with the heritage of Byzantine music, when their cantors sing monodic chant out of the traditional chant books such as the Sticherarion, which in fact consisted of five books, and the Irmologion.
Byzantine music did not disappear after the fall of Constantinople. Its traditions continued under the Patriarch of Constantinople, who after the Ottoman conquest in 1453 was granted administrative responsibilities over all Eastern Orthodox Christians in the Ottoman Empire. During the decline of the Ottoman Empire in the 19th century, burgeoning splinter nations in the Balkans declared autonomy or autocephaly from the Patriarchate of Constantinople. The new self-declared patriarchates were independent nations defined by their religion.