OK, this is getting pretty fine, maybe bordering on navel gazing, but how does one tell if a tune is E Dorian or E Minor when it doesn’t have a C? Do you care? (Unless you are posting to TheSession and you have to pick one) Do you just go with the lesser of the sharps? And let the harmonica player pick his D or G harmonica at random? What happens to the poor guitar player? Do all his chords work regardless of his choice, or will the sound of the tune being played give it away? Hmmm…
If it’s Irish, I assume it’s ‘really’ dorian, on the grounds that dorian tunes are more prevalent in ITM. Other than that, I don’t think it matters, 'cos if it’s a trad tune, the tune itself, being gapped, won’t ever have that degree of the scale in it, and there ‘shouldn’t’ be accompaniment (is there a mildly tongue-in-cheek smiley?). If there happens to be a guitarist, I’ll just tell him which way to play it, but often it’s nice if you can get a guitarist who will simply leave out that degree of the scale, even when playing chords throughout. Preserves the ambiguity, don’t you know …
Oh, and by the way, I would never tell a guitarist it was in “E dorian”. He wouldn’t understand, poor dab …
I’ll try that tonite and let you know what his reaction is. Thanks
That’s the bloody truth… 7 years of piano, 15 years on violin and I’d never heard of dorian, mixolyidian, etc. until I came here. Major and Minor, that’s what you get in the standard musical training. Nobody wants to touch “modes,” just “keys.” Fascists. Musical fascists, the lot of them! 
as a lead guitar player for several groups over the years (one irish), i actually did learn about modes and started goofing with them about 20 years ago… but, i’m probably the exception, not the rule… around here the joke is: how do you get a room full of guitar players to be quiet? ans: put sheet music in front of them. (it usually shuts me right up!)
be well,
jim
I have a practical example of what I would like from a guitarist (apart from shutting up completely 
) for the sort of tune we’re talking about, in E (dor or min) with no 6th degree:
I wouldn’t want any chords of Amin, Cmaj or, Heaven Forfend!, and for different reasons, Bmaj. It’d be fine with me if they just stuck to chords of Emin, Dmaj, Gmaj with, potentially, and sparingly, the odd chord of Bmin. But I reckon a guitarist steeped in the tradition (ha!) would know that in any case.
There is a special case to be made for the occasional inclusion of Amaj chords, given the right tune, even where the mode is, in fact, gapped. But, personally, if it’s gapped, I’d rather it stayed that way, so, where an A chord seems indicated - try an A ‘power’ chord, ie just A’s and E’s in the chord, no third at all.
out of curiousity? why no Bmaj? i can see why no A (other than root and fifth power formulation)… but… B major is … uhm… B, D & F#… (yup) and two of the three notes of those notes can be found in either Dmaj or Gmaj… just curious… thanks, ben.
also… somebody told me that the guitar as a ITM instrument is actually a relatively new development? true? how new?..
again.. just curious.
be well,
jim (blissfully ignorant)
Guitar as an ITM instrument? Dating that is a little bit of a can of worms, I have to tell you, jiminos. In anything like the numbers found now, my personal opinion would be since the second world war (same as bodhrán). But that seems to be one of those historical ‘facts’ that is awfully difficult to verify. [Did you see what I did back there? Did ya? Did ya? ]
Meanwhile, the chord of Bmaj contains the following notes: B D SHARP and Fsharp. It’s a chord that, in anything like Emin at any rate, really only belongs in classical stuff, modern ‘ITM’ compositions and very very occasional older stuff. IMHO.
I like that sign off. 
Made me wonder … d’ya think one could be ignorantly blissful? hmmm …
… yep … just tried it …
yup, it is D# not D… (i wasn’t born this stupid. i had to work hard to get this way!) oh, well… not only am i blissfully ignorant, but comfortably ignorant as well…
be well,
jim (ignorantly ignorant?)
fortunately, i now limit my irish playing (in the main) to the whistle, and i’ve yet to hit a chord on my whistle… although there was that one fellow with a cord and earplugs… hmmm… nah…
and the irish that i do play on guitar contains not one jig, slip jig, double jig, reel, hornpipe, polka, waltz or air… just a bunch of inciteful beer drinking, fighting, romantic little ditties such as Johnny Jump Up and other fine ballads.
be well,
cord-ially yers,
jim
Carey … As both a melody player and a guitarist, my basic answer is: No, I don’t care, unless I have to care.
For any given tune, it depends on the implied harmonic countour. If the V chord or Vm chord (with underlying Phrygian scale) seems to be the Dominant, then it’s probably more minor. If the flat VII seems to be the Dominant chord, then it’s probably more Dorian. This is complicated by the fact that the Vm(7) chord is a common substitution for the Dorian flat VII(6), which makes for lots of ambiguity. Also, in E minorish tunes, that C note is very flexible, and in practice may be played as a C or C# or a C supernatural or something in between.
E minorish tunes that alternate strongly with sections of G Major tonality are easier to conceptualize as Aeolian minor, with Em as the relative minor of G. While tunes that avoid the relative major may sound more Dorian.
As Ben says, there are very few E minorish tunes that seem to suggest a I minor - IV - V Major pattern. For example, The White Petticoat is one the few that will accept a B Major chord as the dominant (with something like an underlying Ahava Raba scale). And the stressed C-nats throughout pretty much peg it as Aeolian minor.
As for the use of guitar … As with much else in traditional music, I think it’s pretty much a case of gesunkenes Kulturgut (look it up). Instruments come into the tradition when they’re cheap and available and accepted in the general culture. This happened with guitars in the late 60s and early 70s following the great folk scare and rock boom, which put guitar in the hands and ears of that generation of musicians - The Dubliners, Sweeney’s Men, et al. Before that, as in other popular music, piano or keyboards would have been the default choice for chordal fill, if any. Or in the case of Irish trad, harp, or accordion Stradella. C.f. the infamous piano accompaniment on Coleman’s discs, and Ó Riada’s use of harpsichord in Ceoltóirí Chualann.
thanks, MT and Ben.
lil ol ignorant me,
be well,
jim
One of these days, I’m going to read an MT post and say, “Yes, of course.” One of these days…
It’s just the “reading” (and writing) part that’s befuddling, Walrus - all the damn terms and words. Give me two minutes sitting in front of you with a guitar, and you’ll say “yes, of course!” It’s actually pretty intuitive stuff.
Awesome!
It is very cool that people know this kind of stuff.
john returns to trying not to play chords on his whistle…
…john
[ 
forgot to post this last night - here it was all ready … I’ll post it now anyway …]
Ah, well now, I understood (and I haven’t looked it up, so I may well have understood wrong) that that piano on the Coleman recordings wasn’t - for the most part - Irish traditional at all. I thought it was added on by the record producers because otherwise people wouldn’t accept the music ‘unadorned’ as it were.
But, as I say, I could well be wrong, and there are some - not many - of those Coleman recordings where the piano is actually quite good. Honest …
And yep, the White Petticoat is a bit different, isn’t it? One of my all-time favourite tunes, as it happens.
BTW, are you sure you don’t care, MTGuru?
Tunes are melodies.
Mode is a melody descriptor.
A tune with the following notes
E F# G A B D E
could be described as either gapped E Dorian
or gapped E Aeolian.
(Western music theory doesn’t have proper names for these modes and therefore has to make do with amending diatonic descriptors to cater for its revived appreciation of its own melodic material).
Both are minor modes in as much as they both have a minor third degree.
E minor only tells you
1.the name of the natural minor KEY SIGNATURE that comprehends these notes
(however, given that the notes decribe a “gapped” series, the key signatire will not be exclusive).
2. the chord you get if you use the modal tonic as the root.
I don’t know how correct this is but an ITM guitarist friend of mine describes such a mode as “sawmill mode”.
Another blues guitarist calls it as “delta blues mode”
In indic tradition Plaasi and Suha are folk oriented raags with this scale, namely
1 2 b3 4 5 b7 8.
Interestingly both are classed as gapped scale raags under the Dorian header (Kaafi Thaat) in the modern system of hindustani classification. (Raags that obtain a wet, rainy or misty valley feeling have a tendency to find themselves under the Dorian header).
From a chordal harmony perspecttive, the Dorian 6th interval is the weakest interval because it cannot be the root of any harmonic triad. IMO omitting it from the scale “strengthens” the dorian modality of the series. It however weakens its harmonicity because it lessens the option of minor chords available from that group of notes. Normally these would have been minor chords with the first, fifth and the 2nd degrees (of the mode) as the root. The last one is not possible now becasue of the absence of the C#.
(last sentence ediited)
To all:
Thanks for the insightful replies. I was going to e-mail the question to MT directly but thought there might be some benefit to the group here having a go at it too. Glad I did. It’s pretty much what I thought. But fer sher I didn’t have the words to say it. What I take away is - if there’s a note missin’ in the tune, have the guitar miss it out in the chords too and see if you like it. It’s prolly missin’ for a reason.