Ok then... musical notation would have to be a lot more recent innovation than from Biblical times. The Psalms were songs meant to be accompanied by instrumentation as can be seen from some of the performance instructions included with them. eg
Psa 4:1 For the Chief Musician; on stringed instruments. A Psalm of David. Answer me when I call, O God of my righteousness; Thou hast set me at large when I was in distress: Have mercy upon me, and hear my prayer.
Psa 5:1 For the Chief Musician; with the Nehiloth. (probably something like a flute)
Psa 8:1 For the Chief Musician; set to the Gittith (harp).
Also Psalms were addressed to 'The Chief Musician' which would mean that they had groups or choirs to perform many of those pieces. Some of the Levites were appointed as musicians and singers 1Ch 15:19-22 so, in the Old Testament (at least), singing was done in groups. In the New Testament you have both individual singers who prophesy in song 1 Co 15:26 but there must also be a corporate song else how could teaching in song Col 3:16 be achieved? The other thing is, it seems, some Psalms were set to pre-existing music... the same as some hymns were set to popular music at the time they were written. I do not know how the Psalms were sung, in the original language, but in biblical times they would have been sung often enough so that everyone would know the tune... probably from the time that they were children.
Psa 9:1 For the Chief Musician; set to Muth-labben.
As for 4 part harmony... that's something we in 'civilized' society seem to have forgotten how to do. We've stepped back and allowed others to do that while we watch (it seems). My brethren in our New Guinea fellowships do the multipart harmonies as just a natural part of their singing. In my fellowship we were taught to listen to other singers and then find a part to fit together with them. (I just have to anyway... I am pretty bass-ic so carrying a melody is not really the best use of my voice).
Not sure how often people gathered together within Jewish society but it seems like each community would have had some point of gathering, as can be seen when Paul, on his missionary journeys, would first go to the synagogue in each town (eg Act 17:1, 17:10, 17:17, 18:4), and, over the centuries, they added many other times of ceremony or celebration than just the main feasts. Singing, either by appointed singers or by the congregation, would have to have been a part of that. I suppose the current Jewish community, if that was the case, would still reflect that kind of song.
Sorry I cannot be more detailed about the place and purpose of music within our congregations... I've forgotten much of what has been taught from our pulpit on this matter and it would take a while for me to find (and re-read) the books that the ministers have written on the subject. It's been about 20 years since we last had a lot of studies done in this area and that was culmination of the previous 30 years of scriptural research on the subject.
So Ggz... I guess the strings, brass and percussion sections in the orchestra at my fellowship my be a bit too light on, these days, to perform your music (it's only half... or maybe a third... of what we use to have) but perhaps our Brisbane fellowship might be able to do it... all though... they're probably only putting maybe 30 or so musicians in the orchestra these days.
