Is high G the highest key whistle made?
It would be tough to make something higher. You might want to try a garklein recorder, which is roughly the c above g. The first finger hole is at most an inch below the windway.
Have never seen a musical whistle higher than high G. Any talented whistle maker could make one, but it’s getting into sports whistle frequency range. More of a special effects instrument, like the piccolo trumpet on Penny Lane, by the Beatles?
https://www.youtube.com/watch?v=WeCKAWQvXzQ
I once tried a “Garklein” and couldn’t even get my fingers next to each other. The smalles recorder I can play is a sopranino. And even then it’s a tight fit. I can play the Generation F however. Never tried the G though.
The Gen F is relatively easy, the G is just playable, with my fingers. 
Custom whistles for the tweeters…
http://www.mixedflockorchestra.net/?content=Lamy%20bird%20whistles
if you’re into that sort of thing.
Interesting! Anyplace to hear some audio samples? I could find any on the website.
For audio clips you would have to contact the maker, Andy Lamy, thru the website. I do know that the whistles are very well made.
Here in the Penny Whistle Museum, Room 1 Exhibit 4, we can see our own Daniel Bingamon’s wee high d whistle. This is an octave higher than the standard “high d” whistle.
Even that’s not the highest key whistle!
Whilst in Room 2 Exhibit 8, you have one of John Orth’s wee high g bird flageolets. That would be an octave higher than the “high g” whistles that Generation make.
Wow, I probably couldn’t get my fingers on the “high-high” D.
‘the slide facilitates the playing of this very tiny whistle.’
Wow that’s tiny. I’ve played a high G whistle and my fingers starting to lock up, it’s a little cramped. High-High D I could maybe train a squirrel to play while I harmonize on alto G some selections from the Nutcracker Suite.
It does. Just have to channel your inner trombonist. And not get too carried away! I once asked Daniel if he could make one without the slide and shifting the two middle holes round back. This would make it entirely playable without the slide. The tiny g whistle is quite playable in that configuration.
Here’s another option just found:
Nick Metcalf demonstrating his high whistles in high F, high G and HIGH A, in the Silverstar model. Sounds fine to me; clear, good tone.
[Thread revival. - Mod]
The first “Tiny D Whistle” I made started out as a Christmas tree ornament per end user request. The first one had a hook in the back for mounting on the tree and yet it was still designed to play in tune.
Then someone wanted a way to play it so I designed one with the slide to uncover the toneholes.
So unlike a “trombone” or “slide whistle” it has calibrated tonehole positions to play the right note. You can also ornament your notes be partially covering holes using the slide.
You would loose the tuning capability but this slide thing could be done on a full size whistle as well.
This youTube video has some nice samples and background info about these bird song whistles:
And this video shows in detail how they are made. Clearly, a lot of care and attention to detail goes into making one of these beauties. The quality of his work on these, and the depth of his knowledge in their use, are truly inspiring.
That’s cool Daniel, the Hizaj scale whistle.
(“Hijaz” is the name for the scale in Arabic musicology, I don’t know if there’s a Hebrew name for it. It’s a common scale in Bulgarian music too.)
When I’ve played that scale on whistle I use a different spot, putting tape on the F# hole and B hole to get B flat and F natural, or half-holing those notes:
A
Bb
C#
D
E
F (natural)
G
a
I used to play in a band that did Bulgarian, Macedonian, Israeli, Serbian, etc folk dance music and I played in that scale quite a bit on my keyed Irish flute, and on whistle.