There are lots of great tunes in A - mainly scottish ones. How do you play them?
I see three ways:
What way do you choose?
You may want to try an E whistle (if you can find one), if you play on an F you are playing them in Bflat
I come across few tunes in A but would stick to the D for them usually. Offcourse if they are the right kind (pentatonic ones, like the Foxhunter’s Reel or Out on the Ocean) you can cheat by using the ‘capo’ method and move up all fingers one position and play as if you were playing in G.
Low E whistle.
Low E is good idea, but that’s a low whistle. Playing low whistles (as for me) is a different story, and I’m not sure I want starting it right now.
Why not transpose to G and play on a D whistle? That’s what I do if there are too many G#s…
Pat
I ended up getting a Low A, more because I liked the sound than because I needed it for tunes in A. It wasn’t much of a stretch to learn; it’s not as bad as some of the other Low keys.
Bregwas: I think, unless you want to play Xb tunes, C,D,E whistles are mostly sufficient (when they aren´t, it has to do something in 3rd octave).
On all of those, you can simply play “sister” (F,G,A respectively to C,D,E) octaves by moving whole tune three holes higher. I. e. for A tunes, I´d simply get an E whistle…
It depends on which “A” key the tune is in.
For the Scottish tunes, such as Scottish Highland pipe tunes, which are in A Mixolydian, I just play them on a D instrument.
For the tunes (Scottish and Irish) in A major, I play them in G major on a low E whistle. An example is Foxhunter’s Reel, which you’ll hear played in both keys (G and A).
Though there’s at least one A major reel, The Linen Cap, that I’ve done what you suggest, restructure the melody so that it has no G sharps in it. That’s because my band plays it in a medley with tunes in A mixolydian and A dorian and I don’t want to switch instruments.
It’s a Cape Breton thing, to play a medley of reels in the same key, but different modes, gradually removing sharps as it were, going A major to A mixolydian to A dorian and/or A minor. I put together a medley of Irish reels that do the same thing, which starts with the A major reel The Linen Cap.
I find a high E whistle useful for this purpose. Also, getting comfortable with half-holing a G#.
Yeah, if high E is too small for you and low E is too big, then you’d better start practicing half-holing G#s on your D whistle. That’s a useful skill to have anyway…
I usually use a D whistle. I either half hole the G# or finger it thus, depending on the tune/whistle:
lower octave: XXO XXX
upper octave XXO XOX
Yes. 
Well… OK, I don’t use the F whistle (because I haven’t 'WhOA’d that far yet), but I do 1 with the half-holing, & 3.
Leave 'em to the fiddlers.
I also use three ways;
Providing the tunes do not go below A,
Otherwise;
Geoff
Why would you cross finger to get the C# for A Mixo’s 3rd when you it comes so naturally without getting cross on a D tube?
Is it for to play “She Moved through the Fair” in A mix such that the bell note G is the lowest 7th that the air asks for?
What happened to me was that when I’d been playing about 11 months, I discovered a couple of must-play tunes in A… well, tunes in modes with 3 sharps… and let them problem motivate me into learning to half-hole the g#. It wasn’t as hard as I thought it would be, though needing to nudge it into tune was kind of stressful.
I insist that it wasn’t that hard, yet the end result was that I said to myself “why not just learn to play these on the rcrd*r??? it’s frigging chromatic..” They were just English folk tunes, after all. So that led to digging out and remembering how to play the fipple flute which must not be named, and that took so much time that I ended up forgetting to play the whistle…
Anyway, I think I got kind of overwhelmed or something by the half-holing (though I will continue to insist that it really wasn’t that hard to do), and ended up not playing the whistle for months.
But I am really un-coordinated and easily stressed out by musical endeavors. If you’re of even average talent, you’ll do much better than me.
And as soon as I catch up to where I was before I quit playing, I plan to start learning to half-hole again. It’s a good skill to have, and then after all, if it’s not that hard, why not learn it?
In my case, I guess ignorance is bliss. No one ever told me that you’re not supposed to be able to play in A major on a D whistle. So I play A tunes like any other tunes. Most whistles I’ve played have a very usable cross-fingered g# in the second octave. And you can half-hole or cross-fudge the lower G#, which seems to occur less frequently anyway. So I don’t really understand the problem. Just play the chunes. 
I do keep a high E whistle in my kit, when I want to play in G fingering. The Susato narrow bore high E is cheap, available, and sounds pretty good. The E whistle also avoids problems of mismatched range and octave folding that occur with many A tunes on an A whistle.
Here’s an old clip of Calliope House (in EMaj) on my Susato E:
http://www.whistlethis.com/utunes/3836f1b4045f251549064268c7da8a78.mp3
Thanks Peter for the reminder about the “whistle capo” trick! This can be a lot of fun to play with. And it doesn’t have to be limited to pentatonic tunes. The crossed and half-holed G#s are still available, as are c and c#. And if you use your bottom pinkie finger to cover the lowest hole, the Ds are there, too. Here are some modified fingerings:
D: xxxxxx|x |x = pinkie
G#: xxx@oo @ = half-hole
c: xoxxoo ooxxxo|x
c#: xoooooo
d: xxxxxx|x or xoxxxx|x
g#: xxx@oo or xxx0xx
c’: xoxxxx or ooxxxo|x
You have to rethink some cuts and rolls (e.g., just try to cut what is now the fingered A with your ghostly first finger, a strange feeling!). But that’s part of the fun. The capo trick is also interesting for playing E Dorian tunes with what is effectively a D Dorian fingering.