See http://www.mlahanas.de/Greeks/Medieval/LX/ByzantineMusic.html (original text by D. Conomos, contains interesting images/icons too).
I copy an interesting quote by St Ignatius:
The second, less permanent, concept was that of koinonia or "communion." This was less permanent because, after the fourth century, when it was analyzed and integrated into a theological system, the bond and "oneness" that united the clergy and the faithful in liturgical worship was less potent. It is, however, one of the key ideas for understanding a number of realities for which we now have different names. With regard to musical performance, this concept of koinonia may be applied to the primitive use of the word choros. It referred, not to a separate group within the congregation entrusted with musical responsibilities, but to the congregation as a whole. St. Ignatius wrote to the Church in Ephesus in the following way:
"You must every man of you join in a choir so that bring harmonious and in concord and taking the keynote of God in unison, you may sing with one voice through Jesus Christ to the Father, so that He may hear you and through your good deeds recognize that you are parts of His Son."
I copy an interesting quote by St Ignatius:
The second, less permanent, concept was that of koinonia or "communion." This was less permanent because, after the fourth century, when it was analyzed and integrated into a theological system, the bond and "oneness" that united the clergy and the faithful in liturgical worship was less potent. It is, however, one of the key ideas for understanding a number of realities for which we now have different names. With regard to musical performance, this concept of koinonia may be applied to the primitive use of the word choros. It referred, not to a separate group within the congregation entrusted with musical responsibilities, but to the congregation as a whole. St. Ignatius wrote to the Church in Ephesus in the following way:
"You must every man of you join in a choir so that bring harmonious and in concord and taking the keynote of God in unison, you may sing with one voice through Jesus Christ to the Father, so that He may hear you and through your good deeds recognize that you are parts of His Son."