I’ve come discover that my favorite whistle key is A (followed by Bb)–it’s high enough to still sound whistle-y and yet the upper octave is low enough not to be piercing or shrill. So I’m curious as to what recommendations people might offer for A (or maybe Bb) whistles–the main characteristic I’m looking for is agility. (In terms of playability, I want a whistle that has more high whistle allegiances than low.) In terms of tone and price, I’m open…
Micah
I have a Dixon Mezzo-Soprano A that I truly love. It plays quite easily and has a lovely tone in both octaves. I guess I’d call it mellow.
I don’t have a Bb yet, but I have a Hoover aluminum/Whitecap on order. I can give you an opinion in a few weeks.
I have a Dixon Bb which I keep within reach most of the time for easy play. I play more flute than whistle but when I see or hear a tune unfamiliar to me ( and there are thousands of those ) I often reach for the Bb and give 'em a go. Dixon makes good stuff. If I find it really catches me then I ABC it and go for the flute - depending which one it sounds better on. I find it easier to grab a whistle and play the tune than it is to grab a flute (maybe put it together if not a delrin).
BillG
I’ve played them all, and I have to recommend a (wooden) Thin Weasel by Glenn Schultz.
Burke Composite
Beautiful sound. Not too pure but pure enough. Woody sound. Blends well with other instruments but can stand alone if need be
My opinion, obviously
jim d
I have a Hoover Whitecap alumium A that I like a lot. As you said, the upper octave being less shrill is a real plus.
The octaves are balanced as well as any of my D whistles. Playing in approximately the same range (first octave D and E, for example), it seems to be the loudest of my whistles (tweaked Clarke original D, Whitecap/Feadog D, Dixon PVC D, Burke narrow bore aluminum D, Burke wide bore brass C).
It’s nice both for slow airs, which is what I mostly work on, and for bluesy pieces, like “Summertime” and “St. James Infirmary”. I can get a pretty good bit of expression out of it with vibrato, slides, and note-bending.
I’ve just been learning “The Dear Irish Boy” from “Mel Bay’s Complete Irish Tin Whistle Book”, which has the music written in B minor for the D whistle, but has the recorded version played on the A whistle. It goes all the way up to third-octave D as written, but by transposing it to E minor in the written version and playing it on the A whistle, I can play it an octave lower, which is much, much nicer, and, I can play along with the CD, as well.
I have a Sindt A/Bb combo set.
Hardly ever play the Bb, but frequently play the A.
Great sound, easy to play, doesn’t require much air. Price is right too.
Best thing about the A is that you can play the key of D with it.
Happy picking.
Mike
One of my consistently favorite whistles over the past 3 years has been my Water Weasel Bb. If you don’t have the cash for a wooden whistle from Glenn, try a Water Weasel…I think his Bb & A’s really excell.
I’ve also heard nice things about Overton A’s (Colin said it’s his favorite key), but I’ve not had a chance to try one.
-Brett
Micah, I’ve sent you a PM
Bill Whedon
Serpent Music
The Sindt A I had was just superb. This is the lowest whistle John makes. I think it’s very nimble.
The Sindt ‘A’ also has a full tone.It’s maybe the nearest thing that you’d get to a ‘good’ Generation ‘A’, if they ever decided to introduce an ‘A’ model!
One for the ‘Trad’ fans! 
a while back, i went on a quest for a good a. cash was an object for me - so i didn’t try the thin weasel as jessie suggested (although i do now have a thin weasel d and absolutely love it!). i tried several in the mid to low range market. i have stuck with a hoover a. its quite good imo. a close second, although they sound totally different, was a chieftian a.
Sindt A is good if you want to use it for D tunes. 
Great. I read the post. Now I need a whistle in A. I bet yall enjoy drinking beer in front of recovering alcoholics, too.
I just got a Thin Weasel Honduras Rosewood in A by Glenn Schultz last week. Just getting used to the whistle, but it seems to be what I was looking for in tone; in fact the wood characteristic in the tone is better than what I was hoping for. The added value is the look of this beauty; truely a great piece of craftmanship and art.
I would easily recommend one!
I’ve got one of Bill Whedon’s metal whistles in A and it’s a really nice whistle.
It gets some session play…about the only non-D whistle I have that does get regularly played in public.
–James
Thanks for the tips, all.
Micah
I’ve played quite a few of whistles in those keys and own some very nice ones. For what you want, I’d have to recommend an A/Bb Sindt combo—relatively cheap, very responsive and high-whistly. I love my Abells and Overtons in those keys but don’t think they’re quite what you want.
I haven’t tried a Thin Weasel that low, but judging from my D, I’d suspect that they’d be very responsive. A Jerry-tweaked Generation Bb would be well worth considering too.