I’m going to write out the things I notice about Hildegard’s chants bit by bit.

This is going to be a technical description so if you are not familiar with these terms you may find this bazaar.

1) Each chant phrase has a destination and it seems to be something like %50 1 / %45 5 and %5 other, at least in what I”m hearing so far.
2) There are also elements that are not quarters that seem to maybe be inprov embellishments. I don’t know if they are, but I can use them if I write them out. Since it is for choir I need to write them out to be specific.
3) In everything I’ve heard I do not hear a major 7 anywhere. It is always a flat 7; still has a tendency to go to 1
4) Scale degree 3 is not particularly emphasized the way we emphasize it now. I can’t recall a time I’ve heard where 3 is the destination
5) I have heard times where 2 is the destination and the following phrase starts on 1
6) Once in a while I will hear a phrase start on the minor 7 but in almost every other case I can recall at this moment phrases start on 1 or 5. I can’t think off the top of my head examples of phrases starting on 1 and ending on 5. I think 1 goes to 1, 5 goes to 5, 5 goes sometimes 1. This needs more listening to figure this out.
7) The melismas are enormous and the phrases are often about as long as you can get in one breath
8) Hildegard is not afraid of high notes. Also her phrases have big curves and shape to them – they are nothing like a drone. I think a significant part of this is that low 1, 5, and high 1 are all valid places to end a phrase and that makes things rangy.
9) I heard one with two part counterpoint. This was had the rhythm tied – the words were always tied together and there was no imitation in what I heard. It was not all too far away from Fux 2 part although one key difference is that parallel fifths and octaves are allowed. I don’t think I heard any parallel fourths.
10) Rhythm: We’re dealing with old notation, but to keep things simple I’m going to call the general pulse a quarter note. Using this I’ll say that there is no fear of 8th notes. And I hear things that might be closer to 8th note triplets than anything else. In the two parts, the counterpoint occasionally cadences into a unison, then moves away with contrary motion and I think this tends to happen on the 5th of the mode. Cadences are not always the same length. Sometimes they are quarters, more or less, and whole notes, more or less. Sometimes cadences seem to be preceded by a half note, but usually it is a quarter note with a slight rit or tiny fermata on it. In general half notes do not seem to appear except as the length of the pause / rest between phrases. Half note rests are all over the place.
11) Minor third hops: Sometimes when reaching a high 1 there will be an expressive leap up a minor third that then comes right back to the high 1. Same thing, less common, with a 5th hopping to a minor 7 and then back.
12) Tempo: These all tend to be about same rhythms which is moves right along with quarter equals about 120. That said the tempo is not strict, but when I do this if I do have counterpoint where things are not all locked into the same rhythm, I may well have to quantify every beat and keep in strict tempo most or near all of the time.
13) Some of these don’t hover on melismas, sometimes these go through a lot of text very quickly. My piece doesn’t have a lot of text so I would ned to melisma it out and repeat some.