I understand what folks are getting at regarding the swung notes and references to the click track timings for them - although I "see it" differently.    What I read into it is that the two 1/8ths duplet (making a 1/4 note time overall) should be played as a 1/4 note triplet consisting of two notes.  The overall time of the triplet MUST be a 1/4 note and the triplet is then effectively 3 "beats" making up the time of 1/4 note.  The first note of the triplet (drawn as a 1/4 note) consists of 2 of these beats and the final note of the triplet (drawn as an 1/8th note) makes up the third of these beats.

So - within the timing of the triplet "each of the three beats making up the triplet" is 1/12th note long  ( 3/12 notes for the entire triplet = 1/4 note, as intended ) - so the first swung note (shown as a 1/4 in the triplet) is to be played as a 2/12 (or 1/6) note in duration, and the second (final) note (shown as a 1/8th)  in the triplet is to be played as a 1/12 beat.

This surely makes it "difficult" to notate (beats normally being powers of 2 in time - 1, 1/2, 1/4, 1/8, 1/16 etc etc ) and "defeats" the basic integral timing of the software creating the click track.  I accept, yes, of course, there are ways this could be done - but equally - it's my feeling that it's just a case of using the click as a guide - and you know (because of the instruction) to swing the note pair. 

I interpret such an "instruction" as being not much different (well, yes it is a different thing of course, but in some ways similar - let's call it that - an "instruction") from other "instructions" in a score - such as introducing dim or cresc, or rit etc - your individual "dim", "cresc" or "rit" may well be (in fact generally WILL BE) different in absolute timing from others - it's just a "general indication" - i.e. how rapidly, or slowly you incorporate the diminuendo/crescendo over "x" bars and precisely how you perform the "rit" - these are indeed different from other players' interpretations - and even different solo/individual performances by the same player  can easily differ "in the moment of playing" between performances.  Just "swing" the duplet/"instructed swung triplet" note pair as best you can !

Not necessarily the "correct interpretation",  just my way of seeing it....

Yup @Gordon Shumway - expressed in a much more concise manner than I - but equally getting to the point !

 Don't underestimate the jazz big band!

LOL - that sums up what I was struggling to say ! Thanks !

grandpafiddle said
Whew!

I'm just going to play a regular style "Let It Snow" on my fiddle and send it to Pierre.

He'll put it all together and make it sound great!

grandpa  

indeed @Grandpafiddle - well said - that is actually ALL that is needed.    What is often forgotten is, in a project like this, is that we, the players, are simply NOT SOLOING - we are a massed-band-of-players - listen to any large orchestral piece - it is indeed the many, many, small, but subtle differences in timing say in a violin section that gives it the final overall sound which we, as listeners, hear.  The difference (for one, single, individual (even many) player/s) playing the triplet as a dotted 1/8th ( 3/16ths) followed by a 1/16th = 4/16th = the expected 1/4 note of course - for what we are doing - really will make no difference whatsoever to the overall mix where there are possibly in excess of 100 mixed-down audio tracks ( well, ok, some minor difference - but - truly - this is splitting hairs - because quite simply - no two players will ever have the same exact timing - it is as simple as that. It will all come out fine in the final mix down, it always does)

He'll put it all together and make it sound great!

Precisely, and well said @Grandpafiddle 

LOL @ELCBK  - but yes - if you are referring to the intended "swing" (which, to me, is just a notification/indication to the player while following the SCORE ) - it (the click track) "will" indeed sound "off".   Pretty much as I described earlier - no disagreement about that.  It HAS to be "off" in this simplified scenario I believe.  That's precisely what I was getting at - but - I see nothing "wrong with that" - it IS the way it IS..  we just need to be aware of what the arranger WANTS (by the indication of the swing)

The triplet indication at the top of the score is for the human player to interpret appropriately - the click we hear is an automated, synthed, drum-beat-mix based on 4/4 and not 12/12 (which would be needed for the click/drum to be timed correctly - but ONLY for the paired-eighth-notes played as a quarter-note-triplet) - it is a "guide" in this case, and is not a "do precisely what I do when you see the intended triplets in the score" - rather "remember what was indicated about the "twin-eighth's" when you hit them and "play to fit" the apparent 3-beats in the one-quarter-note-triplet into ONE quarter note....  hmmm - the significant point being, these 1/8th pairs are, as indicated, really a 1/4 note triplet timing....   and, sorry ELCB - here and now - I just cannot see past my understanding of this (but as ever, quite naturally stand to be corrected/enlightened) - sure - I agree - it doesn't "sound right" - but it is just a click, an "indicator", nothing more - just as any score is.....  Just the way I see it !