From Michael Ruse:
Reader Matt Groh will present some exotic material on local church singing from the Balkans and the Caucasus regions, neighboring places of Russia. He is also an educator by profession and he teaches science. Since he is the head chanter at St. John’s, you will not want to miss his presentation on local Orthodox church singing. Join us this Saturday at 4:00 pm.
The country of Georgia is located in the Caucasus Mountains on the border of Asia and Europe, and both Bulgaria and Serbia are situated in the Balkans. The last two countries have grown out of Slavonic and Hellenic church singing traditions and they are still influential today. They have a unique melodic development while they also share a Byzantine tradition based on the eight-tones like Russian chants.
The amount of voices used is an accurate and convenient way to categorize church singing in different countries. We can place the ancient traditions of Constantinople, Alexandria, and Antioch under the one-voiced type sung with an ison-drone (bass drone). That type of singing is also used in modern Hellenic, Bulgarian, and Russian lands. Four-voiced homophono-harmonic or part-singing is widespread in Russia, Serbia, Bulgaria, Finland, Japan, America, the Czech and Slovak lands, and Poland. Finally, there is the Georgian three-voiced that is a "unison" type of singing because of its characteristic cadence that grows into one voice. This chapter reveals the Orthodox mind because church singing is varied and unified at the same time.