Have you seen the accompaniment for Mass I in the Liber Cantualis comitante organo by the Monks of Solesmes? Looks like you can view some of it here. I use this volume of chant accompaniments all the time.

When do you need it? Sounds like a good project to improve my organ writing ...

Yes but: some folks want to have a new thing three months before its use, others are calm with day-before delivery .. the Ra,czkowsky (Polish Kyriale) linked above is a harmonization, one of those that follows the chant rhythm and adds notes below the chant melody which are plausible harmonic material. That's not the kind of thing I read when reading the original post, but it's not entirely clear what is wanted.

I wrote this yesterday. If you like it and would like me to do the rest of the mass we can discuss that possibility.

I opted for standard notation instead of the NOH stemless look, because some of the figures make more sense visually this way.

It is intended to be useful no matter what type of registration is selected. Attached are midi recordings of full organ or flute - the harmonies sound "lush and jubilant" either way.

Wow. Thanks, everyone, for your replies. Yes @Salieri, I'm planning for Easter, already. ;) I didn't expect anyone to compose anything on my behalf; in fact, I was looking for an accompaniment in the public domain (I know-- I'm so demanding) that I could borrow harmonic material from in my own choral composition.

Unfortunately, I don't have the resources to commission a new work, at present, but I appreciate your willingness to help; and the new work that has been posted above is lovely. @ryand, I love the dissonances in yours-- that certainly is lush!

Also, I've just corrected my original post: I don't think I've actually seen the Rossini accompaniment to this Mass, as I can't find a PDF of it anywhere. Anyone have this? Wink, wink.

Adam: Correct needle. See original post at top.

ryand -- write the whole mass. People will use it.

You may think 'can you see' (SOL LA DO); one might try DO-RE-FA; to my original ears the melody HAS to start RE-MI-SOL, unusual as that may appear.

I like the Solesmes' accompaniments as well, Felipe. They're light and serene. The Liber Cantualis comitante organo is probably my most used organ book. Wish they had accompaniments for all the mass settings.

And with tuning markings and the simplest of bass lines:

you can't do jubilant without rhythm

The corpus of Gregorian Alleluias would seem to disagree with you.

Actually, if sung with a good interpretation following Cardine's principles, with some judiciously added epismata from St. Gall and or Laon, light repercussions (a slight push from the diaphragm) on the bi- and tri-strophs, using epismata as points of expression, and mora vocis as a point of rest, the Gregorian Alleluias are indeed very rhythmic, but it is a different rhythm than that usually associated with mensural music.

I'll commit to playing it at home and thinking about doing it for Mass for Easter of 2016. I promise.

Somehow I just can't think of the typical chant accompaniments by anyone or from any source as either lush or jubilant. Well, I take that back... maybe lush, but, um, 'lush' in a different sense (if you see what I'm saying). But certainly not jubilant. I can think of ways of accompanying chant that would be quite jubilant... but then, the chant would no longer be chant... but then, it isn't anyway when its accompanied in any fashion. The rhythmic freedom, elasticity, and spontaneity are gone

And, Ben and Salieri are both right. Chant rhythm isn't metrical rhythm, but rhythm it has or it's dead, wooden.

I'd do the whole NOH that way if I could eat while doing it.

Is that a problem with hand-eye coordination?

@ryand, it's beautiful, and if you finish writing this in a way that easily translates to SATB choir singing concisely at an EF (and the Kyrie looks like it does), then I will do my best to use it, during the upcoming Paschaltide (2015). When I say "do my best," I mean earnestly try it with my choir over multiple rehearsals to see whether they can do it justice. It would be ideal if ultimately you provide PDF(s) and midi files, so I can easily make recordings of separate parts for choir.

If we can't do it justice in the time we have, then I would still be very keen to use it as an organ accompaniment during Paschaltide, this year.

I suppose you wouldn't write a Credo, anyway, if you were just setting Lux et Origo; but just in case, to be quite honest, if you write both a Gloria and a Credo, and my choir sings the Mass chorally, then we'll probably just do a chant Credo, instead, this time around, for my sanity.

I'll continue writing my own choral setting, either way, with intent to use it at some point this year, as well, but our settings are very different; and I love presenting contrasting music based on the same chants-- I love showing just what a magnificent source of inspiration the chants are. Yes, they are pure and holy and complete on their own, but they are also an endless source of musical (and spiritual) inspiration.

M. Jackson Osborn, LOL at your "lush" comments.

@ryand

Lengthened Notes:
Yes, as far as lengthening notes is concerned, we mostly follow the practices described in the Liber Usualis, and would prefer that the following notes be written as quarter notes:
* 1st note of a quilisma grouping (i.e., the one before the squiggly)
* dotted notes
* the "middle" note of a salicus (i.e., the one with the vertical episema underneath it)
* the top note of an ascending fifth, if it has a vertical episema (for example, the 2nd note of the first syllable of "Pleni" in the Sanctus from Mass I)
* a note with a horizontal episema over it (for example, each of the first three notes of "Christe" in the Kyrie from Mass I); or you could notate these three notes as a triplet, if you prefer.

Really, what you've posted, above, for the Kyrie is quite workable, though.

The Kyrie:
If you wish, you can notate a repeat of the first of each grouping, in the Kyrie, to make it more EF-choir-friendly (3-3-3), or I can just tell my choir to repeat. ;)

Staves:
No need to expand it to 4 staves as long as you (or I) have room to notate the text for the other voices.

The Sanctus:
Yes, we would need the Sanctus and the Benedictus. Here is a link to the full chant (Sanctus-Benedictus): http://www.ccwatershed.org/media/pdfs/12/06/19/16-12-13_0.pdf

In the 1962 EF, if the Sanctus-Benedictus is sung in chant, then it is sung all together; but if it is sung in polyphony, then the Sanctus section is sung at the usual time, and the Benedictus section is saved until after the Consecration. Thus, you may want to make a sort of logical breaking point before the Benedictus text (i.e., after the 1st "Hosanna in excelsis," just in case a choir chooses to break it, there. You don't necessarily have to notate a break, there, but I would definitely recommend ensuring that the music makes sense with or without a complete break.

Time Signatures:
Looks brilliant, as is. The beauty here is that you've kept the rhythm of the chant intact; hence, the conductor can basically just conduct the chant.

I just conducted through this several times, and had no trouble at all; and wow-- conducting this piece gives me chills.

The pickup notes in the lower voices could be however long or brief you'd like, obviously the performance rhythms in this are not as stringent as the mp3s sound.

Sanctus

Lovely.

That's beautiful. Are they just holding out related vowel sounds?

Here is a midi of the Gloria. I did what I could to mimic stop changes. The score is going to take some time to make presentable, but you can at least listen to it for now.

Gloria score

The midi "changes stops" more often than indicated in the score here. I figure those decisions are best left to the organist, in consideration of their own abilities and the instrument at hand. I've noted where I imagine the pedals being used prominently.

Also, typo in Benedictus: should be "in nomine domini" rather than "in nomine domine." FYI.

Ryan, even if just the Gloria, I'd love to have the Gloria in Musescore format; or if you'd prefer, I can work with the midi file, funky and chunky though it be. Trust me: either one will save me time.