Not that I know of. Interesting idea.

There is a youtube channel that was mentioned on here before, Leland Plays RMC. He plays through every tune in the collection, and he has accompaniments with it. I saw several comments asking about the accompaniment, and I even asked myself. Never saw any answers. Not sure if he had a resource or if he came up with all the accompaniments himself?

I recon it requires an algorithm that detects musical clef in a pdf. file. One could then copy/paste into a composition app. Many composition apps can suggest comp chords. Must be AI? 

it doesn't take me long to find the comp chords by ear for one tune. But things are quite different for 1050 tunes.

I got a response from Leland. He said he just followed the usual folk conventions of moving between I, IV, and V. I guess he came up with the accompaniments as he encountered the tunes. All the more impressive.

I think it would be relatively easy for most of it, although I can think of some that might want the relative minor, or even V of V. But the last 30 or so pages have some more oddball stuff, from strathspeys to minstrel show walk arounds. That might be harder. Not that you asked, but in the back of the book there are a lot of exercises that always look like they might be useful, but I've never tried them. I don't guess he included them too.

Be it a guitar, banjer, or mandolin, I strum along in time with the root/key chord. I listen for a (1st) change. I try the IV, or V chord. A minor chord will sound much different, dissonant to me. I also know the tune will resolve to the root/1.

Not that challenging to "come up with" chord changes for traditional music (including Irish, American, or English), and his choices are entirely predictable as one who must have some experience with the music and a chord instrument.

But Doug is right, there may be minor chords especially in anything that might be irishy or Scottish.

fiddlinwolf - Don't know if you know that Andrew Kuntz, the compiler of "The Fiddler's Companion," now the "Traditional Tune Archive," (a mammoth collection if ever there was one) wrote quite a few articles for "Fiddler" magazine, including four about "Ryan's." ibiblio.org/fiddlers/Articles.htm The link to the fourth one is broken, but perhaps it can be accessed some other way. PS - I think part 4 may have been appended to part 3.
The wide range of material included in the collection makes coming up with suitable accompaniment an even more impressve task. Just looking through it last night I was reminded how many truly Scottish and Irish tunes are in there, which would require more subtle accompaniment than just banging out I - IV - V, old time style. Even "Green Fields of America," as a familiar example.
I haven't had a chance to check out Leland's channel, but I will. Thanks for mentioning it.

ChickenMan - That's the problem. A lot of what's in "Ryan's"is not what is considered "traditional" music today (which is what makes it not too useful as a jam session book). There are lots of recent (at the time) compositions about current events, famous people, signature dances of famous performers, clogs of various kinds, strathspeys, and minstrel show instrumentals, different from Stephen Foster type songs.
Check out those articles by Andrew Kuntz. He really did some research.

BTW, for those who have never explored "Ryan's Mammoth Collection" or "Cole's 1000 Fiddle Tunes," there are several places online where it can be downloaded as a .pdf. One problem is that it didn't originally have an index. Several years ago a member here compiled a great, accurate index, which was available as a separate file. I see that some sources now have combined the index with the main file. You should make sure you have that - it makes Ryan's a very useful reference book.

My uneducated theory on the hoof....

i think some of the accompaniment, especially for earlier tunes, would be based on "Divisions of a Ground" (as in Playfords etc), rather than Chords. As chords weren't really the norm until the 18th century. Ie: Bass, Melody and Descant where the norm.

The trouble with most tune books is that you are usually just given the melody, which could be considered to be a "division" of a "Ground" (simple bass line), with added ornaments "Descant".

So you have to invent a "Ground"(simple bass line), which goes with the melody, then add any ornaments on the top. Which BTW may, or may not have already been notated along with the melody. And an implied ground.

Just a slightly different way of thinking about acc, as opposed to the normal more modern triads, and progressions etc.

With the "Divisions On A Ground" way of thinking, you are given a ground to invent an improvised melody on. But if you are given the melody only , you would have to invent the ground for the accompaniment, then add any ornaments.

This way of thinking would facilitate the use of single note instruments to form an accompaniment for a tune....say a Cello For the ground, a fiddle for the melody and a whistle for the descant. maybe?

i think an example of a Scottish tune book with added Ground would be "The Skye Collection" by Keith. Norman. MacDonald. in which you are given a simple (piano), ground that the tunes are based on.

Edit: Or you could tune your guitar to DADGAD, use a capo and wang away merrily...

Pete - Have you ever looked at "Ryan's Mammoth Collection?" It was published in 1883, well into the era of chord based accompanment. Although it does contain many older Irish and Scottish tunes, few, if any date from the time of Playford, or the system you're talking about.
PS - It also long predates DADGAD tuning, which I don't think would even be very useful for most of these tunes. And guitar probaby wasn't even the most common accompanying instrument at that time.
BTW, here is where I downloaded my .pdf copy of "Ryan's" violinsheetmusic.org/collections/ It includes the index. I've also had a couple copies of "Coles" over the years. Like Tommy Jackson's square dance records, it was what was available when I first got interested in fiddle music.

Doug, I'm talking about utilizing what is at hand in the present, (ie: a plethora of guitars). Also most guitarists over here, in any Irish session play in DADGAD to all of the tunes in O'Neill's. Which i believe is a very similar publication to Ryans? And a lot of the tunes will be considerably older than 1883.

Looks like we have come up with the answer between us....Some of em need treating like ancient melodies, others are more modern, and some of em are in between. Just use the appropriate accompaniment. Or as close as you can get with what is at hand. That is unless you want to make Greensleeves into a jazz tune..Probably already done!

"Ryan's" and "O'Neill's" are (very) roughly contemporary, but not really very similar. "O'Neills" contains tunes collected from, or in some cases possibly composed by, members of the Irish - American community in turn of the century Chicago, by a lover of Irish music and culture who was passionate about preserving it and well informed about his topic. "Ryan's" was published by a commercial music publisher in Boston, largely compiled from previous publications, and as I said earlier, contains a much wider collection of music popular at the time. Neither contain many, if any, really old tunes, although even Ryan's has a couple from Niel Gow. BTW, "O'Neill's" has a picture of the members of the Irish music club of Chicago. I see violins, flutes, pipes, but no guitars, DADGAD or otherwise.
I finally had a chance to watch some of Leland's videos, which were the subject of fiddlinwolfe's thread. All the ones I saw had piano accompaniment, generally well done, and completely appropriate to the era AFAIK. I can see how one might wonder if the scores exist somewhere.
Judging from early recordings, at the time of these collections the tunes were probably played solo, or with one or two other melody instruments, or with piano accompaniment. Chief O'Neill even made cylinder recordings of some of his sources, generally playing solo.
Over here you won't find DADGAD tuned guitars (a very modern idea) outside Irish "sessions" (also a quite modern idea) or fingerstyle "folk" guitarists. To me its similar to crosstuning a fiddle and playing simple A tunes for hours - it makes everything sound the same.
Conclusion - Seems to me Leland did a very good job with this project, and it really gives the collectiin a new dimension.
PS - Just saw your last post. I agree that the tunes may need differing approaches, although in Cape Breton most of the Scottish ones would be handled in a similar way. From the few videos I saw it seemed like Leland was having the most trouble with the "essences," which are minstrel showpieces, probably actually played on the banjo, and the notation may not really be very helpful to begin with.

Doug, what i am saying is that the accompaniment for any given tune is dependent on how the player hears it, their skills and what instrument(s) they are playing. In other words it is an arrangement or setting of a tune by a given accompanist, and not a definitive version of the given tune.

I offered a suggestion ( Divisions on a Ground), for an accompaniment for tunes that might predate the published date of "Ryans Mammoth Collection" (which all of the tunes obviously do).

PS: As you say Leland probably did a good job, but to me it would not be definitive. It would be an arrangement by Leland. and it would be subjective as to whether i like it or not.

Personally i prefer DADGAD Acompaniment for a lot of older tunes, and more modern standard Chords/Progressions for other what i would call "Crossover" tunes. But that is just my personal opinion. For instance Dominant 7 chords sound corny to me in some tunes, and great in others. And other tunes just need a drone. But that would just be my preference rather than "The" accompaniment.

I wasn't sure which was which (Ryan's/ Cole's) and then after I posted I thought I was likely thinking of O'Neil's mostly anyway. I have a BUNCH of tune/songbooks given to me in digital form. Should probably look to see if those are there (very likely).

Thanks everyone for the information! I was hoping for a resource to reference but looks like I am out of luck on that front.

Doug,
Thanks for the fiddler's companion links. They were good reads. Mel Bay's version by Patrick Sky has a very thorough history of the collection as well.

Not sure if you have ever come across the ITMA website. It is focused on Irish Trad but has the entire RMC with interactive notation using an embedded sound slice app. Here is a link to the first part of the collection in case you're interested. There are also some other collections on there that have a fiddler playing the notation, like the Joyce collection.
itma.ie/notated-collections/ry...ection-a/

Concerning the O'Neill's and Ryan's comparison, I found this to be of interest. I think the intent was to see if there was any merit to O'Neill lifting tunes from Ryan's.
irishtune.info/public/ryan-oneill.htm

Lastly, if you are interested in ABC notation, John Chamber's site has a lot of these old public domain collections hosted there. O'Neill's and Ryan's are present.
trillian.mit.edu/~jc/music/book/