Jon F, tunable whistles are always likely to be more practical than Generations for rough-and-ready sessions where tuning can wander far and wide either side of concert pitch. The tunable Susato gets my vote among the Ds - they're still cheap at less than a tenner. And the fipple is removable, which can be handy when it's time for a good clean-out.

Here's a thought,Bob. The Susato comes with moveable thumb-rest which I don't suppoe many of us actually need. If you could make a similar collar but with flange rather than thumb-rest, you could make a low-pitch whistle with two bottom holes. The user would decide which to expose for playing purposes, according to his/her handedness, if there's such a word.

But getting back to where this thread started, I very recently read (but cannot now track down) a glorious account, in ludicrous detail, by some crazy man who plays his whistles back to front in hurricanes. Or in the case of tunable whistles, he rotates one half against the other through 180 degrees, so he can have the mouthpiece upside down, with the window sheltered from the elements, but with the holes still where you'd expect to find them.

Somehow (don't ask!) this guy stumbled on the discover that non-tunable whistles can also be played upside down. The holes of course are then in towards the body, but the thing can still be played. You just curl your fingers right round till they reach. He's right, you can play a tune like this. I've atually tried it, in the privacy of my own home. With a bit more practice it will be a bizarre party trick. And that surely must be the last word on whistleplaying al fresco.