Russian Choir of the Holy Blood Church

Sofia Ecclestiastical Choir

St. Michael's Romanian Church Choir

St. Cyril & Methodius Ukrainian Church Choir

Greek Orthodox Polyphonic Chorus of Anthens

Belgrade Singing Society

Armenian Apostolic Chorus of Jerusalem

Georgian Orthodox Choir of Tiflis

Greek Orthodox triphonic Chorus of Athens

Greek Orthodox Tetraphonic Chorus

Greek Orthodox Triphonic Chorus of Anthens