Hans, the point of all this is not actually whether the tune is pentatonic, but that the use of that F# in that first bar made me go uurgh, based on my instincts, taste and experience. I don’t think any amount of examples you can throw at me will change that.
There is plenty of documentary evidence of people playing things in different ways. But we need to bring our own instincts and taste to bear on what we come across. I do anyway. And instincts change over time, of course.
I’m guessing you’re reacting to the F# as not just non-pentatonic, but as the leading tone in Gmaj. And of the two “missing” tones, it’s the one that most suggests conventional art music or common practice, as opposed to whatever trad aesthetic you want to hear in the tune without it. But clearly, not everyone hears or plays it that way as strictly pentatonic.
Personally I tend to play it with a folded-up B on whistle (~G3D EDBD), because the G(6) arpeggio at that point in the tune seems like pretty strong fu to me.
Seconded. 
Playing around with Me. G.'s suggestion to play the B part as fully pentatonic gives a distinctly different feeling to the tune. Perhaps a little more ‘mystic’ or . . .
I admit I hear the version with the F#'s a lot oftener in sessions. . .perhaps I should be more discriminating in the sessions I attend 
Going more modal certainly cannot hurt many Irish tunes. . .
I originally learned this tune with the ‘folded’ up B but also with the F#. Somehow it always seem a little too jolly to be associated with a title like ‘The Banshee’. The general trend in Irish Folklore is that dealings with ‘the Other World’ are chancey at best. . . .
Bob
That reminds me, wasn’t there a story about James O Neil trying to notate a tune and getting frustrated because every time the source player played it, the tune was different?
I think that at least partly the settings reflect the judgments/choices James made as he did the notating, and presumably also the tastes of editor Francis.
As I recall James was a trained violinist and did the notating because Francis was musically illiterate.
Not to pile on poor Michael, but I felt the same thing when I heard him playing Jenny’s Chickens, in which he changed all the notes which are C# in the Matt Molloy version I learned to D. These D’s grated on my ear because everyone I’d heard had used no D’s at all, keeping the ‘gap scale’ nature of the tune intact. The substitution of D for C# turned a tune with no 3rd (and thus harmonically vague) into a straight minor tune.
I do not own that book. Is the version any different from what is published here on
http://tunearch.org/wiki/McMahon's_Reel
(this is the abc transcription by Henrik Norbeck)?
Yes it’s quite different in that the melody doesn’t contain any F#s.
The first figure on the second measure (G,F#,G,B,D)just doesn’t sit well with the rest of the phrase to me. Sounds out of place with the rest of the tune.
If you are the kind of player who thinks in terms of chords - an accompanist, or box player who uses the bass - this means fitting the tune to Bm rather than F#m - bit of a shame, there should be more of F#m in the world.
Maybe Michael likes to surprise us, for which there is precedent after all - “looking for the ‘hidden’ note” (we won’t say ‘wrong’, will we). Not long ago he posted an accordion clip in which he made all the Cs in Trip to Athlone natural, which certainly surprised me!
okay, here is an abc transcription of McMahon’s Reel (The Banshee), which has only fleeting use of F#s in three triplet runs. This is supposed to be a transcription of the version in Ceol Rinnce na hEirreann vol 2 (can’t verify this). This was very hard to find, most versions you find on the web use more F#s, with significant differences to this:
T:McMahon's Reel (The Banshee)
B:CRE2.273 (Ríl Mhic Mhathúna)
M:C
R:reel
K:G
G3D EDEE|DEGB d2Bd|(3efg dB A2GA|BAGE EDD2|
G3D EDB,D|(3EDE GB d2Bd|(3efg dB A2GA|BAGE EDD2:|
eaag egge|dBBA B3d|eBB2 gBB2|eBBA B3d|
eaag egge|dBBA B3d|(3efg dB A2GA|BAGE EDD2:|
And your point is?
I suppose you’ve made it 3 times already: the versions you have found with F#s prove that I was incorrect to say the tune was essentially pentatonic. Well let’s just say that in my mind at least the tune is essentially pentatonic. Happy now?
No, not at all! I agree with you, it being essentially pentatonic, in that version I dug up. And if that corresponds to the oldest printed version so much the better. Seeing the older version I bow my hat and admit that you were right all along. It also shows me how difficult and nearly impossible it is to find an authentic notation on the web.
My point? I just wanted to see.
From what I can gather The Banshee is a fairly modern tune, written by flute player James McMahon, originally from Rosslea, Co. Fermanagh (born circa 1900) (when did he die, or is he still alive?), and also known as McMahon’s Reel [ > http://tunearch.org/wiki/Annotation:McMahon’s_Reel > ].
And I do not see it written as pentatonic, only as hexatonic (gapped scale without C or C#).
For instance > http://tunearch.org/wiki/McMahon’s_Reel
or > http://www.novasession.org/Tunes/bwreels-9.pdf
As a more modern composition, and published as notation in various books, there should not be much argument about a possible pentatonic origin, even though the A part especially is tempting to be played purely pentatonically without F#s.
Hans, the above is what I replied to, the version supplied (from John Loughran, of Co Fermanagh) possibly closest to the source of any version I could come up with at the drop of a hat. And I think it makes the argument convincingly. I don’t think there’s a lot more to say about it.
Thanks, yours and Stevie’s input is very much appreciated, as always! Especially if one has no direct connection to the sources and hopes to find inspiration through web searches, which often can get misleading and frustrating.
In all fairness, I just had a look, ‘Hidden Fermanagh’ does give the Banshee with the turn going eaag efge dBBa B they do not a provide a source for the tune though, just the name of the composer and the fact the Bothy Band recorded it. I must say I find the eaag egge dBBa B a more natural fit but to each their own aesthetic choices. And it is the sort of transition you see happening a lot, where the old players would go straight for the note and the younger crowd adding notes. I suppose the old jigs ending for example BGG G turning into BGF G is something similar: some people vehemently dislike that and feel it spoils the old tunes when you end them that way.
But isn’t that a significant part of the musical tradition? Finding the Ur version only tells you how that person played it (or composed it). Over the years, the versions grow and expand as we’ve seen. I guess that sometimes a version will push “outside the tradition” but, to go back to the OP’s question, “Which one is the ‘real’ one?”
And to continue and expand on the thread drift… Any thoughts on why there might be a significant number of pentatonic tunes in ITM (and I’m basing that on comments here)? Is there some instrument limitation that would lead to this situation?
Thanks and best wishes.
Steve
I got quite a bee in my bonnet about this question of added notes filling in the gaps at some point towards the end of the last century. I have relaxed a lot about it (phew) but I still think it is worth keeping a discerning eye open for.
I once listened to Sean Casey, son of Bobby, playing Christmas Eve on fiddle. He really made a new tune out of it, scattering Cs and F#s liberally all over the place. A new, inventive perhaps, but ultimately character-less tune, I felt - and still feel.
A couple of other examples to ponder:
There’s a tune variously called McGettrick’s or McGorman’s and I don’t know what else, another essentially pentatonic tune (two sharps) that starts (the way I like it)
A3B defa | a2fd edBd …
The dominant tendency nowadays seems to be to play
A3B defg | a2fd edBd
The difference in feeling that little g generates is just enormous. And to my ear, horrible!
Another pentatonic tune, purely pentatonic this one: Humours of Toomagh aka The Cloon. I’ve actually heard people discussing it as being in D minor! which gives them permission to stick a few f nats into the tune, with similarly nauseating results.
Last point, if you deliberately set out to respect what you think is the essential pentatonic (or hexatonic) nature of a tune, to the point of avoiding phrases or variations that just about everybody plays, you can often come up with some nice alternatives.
Second part of Out on the Ocean, just about everybody plays as a variation
ege edB|ege edB|ded def|gfe dBA|
try this instead
ege edB|ege edB|ded dba|ged edB|
Harmless fun.
Edited to fix octave - thank you Ben
High a2?
I’m not familiar with the tune. Looking at the various versions on the net, I’m finding it in D, C, G, “sorta Amin” and others. What key would you use to describe the tune? And what would the first few notes be?
Thanks and best wishes.
Steve