St. Michael's Romanian Church Choir

Russian Choir of the Holy Blood Church

Greek Orthodox Polyphonic Chorus of Anthens

Sofia Ecclestiastical Choir

St. Cyril & Methodius Ukrainian Church Choir

Belgrade Singing Society

Greek Orthodox triphonic Chorus of Athens

Armenian Apostolic Chorus of Jerusalem

Greek Orthodox Tetraphonic Chorus

Georgian Orthodox Choir of Tiflis

Greek Orthodox Triphonic Chorus of Anthens