Answer:
Byzantine chant, monophonic, or unison, liturgical chant of the Greek Orthodox church during the Byzantine Empire (330–1453) and down to the 16th century; in modern Greece the term refers to ecclesiastical music of any period.
That is the essential reason for chanting. Worship at its heart is a song and is beautiful; therefore the words of Orthodox worship cannot be simply said but must be melodiously chanted to express the true nature and purpose of the words.
