Oh, I’m smitten.
I’ve been meaning to do this beauty justice and write a big full-blown review, but I’ve been busy. You’ll have to settle with this for now.
That’s my woefully meager collection of Overtons. Can you spot the D/C modal? It’s as long as the C and right next to blue hi D. You’ll notice the offset c-hole.
Here is a picture from the Overton webpage:
You can see the extra holes: a c-natural hole at the bottom, off-set, and played with the pinky of the bottom hand (which had better be the right hand; unless you have Colin put it on the other side). The other hole is on the back of the whistle and sounds an f-natural, if played like this:
xxx xx(o)oo
The parentheses show the f-natural hole on the back.
Right. That’s a lot of holes for a whistle. I know you all are worried about my health and hirsute fingertips by now, so let me just pause to say: It’s a long way to Moellenhauer. The D/C modal is a whistle and only a whistle. It has nothing to do with other things that may also have fipples. *shudder
Oh, no you don’t.
It’s a D/C modal whistle. So what is it good for? Obviously, you can play a C-major scale on it, not just D-major and G-major. But there are other very cool aspects. That bottom C, below the D, gives you a D-whistle with the ability to dip below the fundamental. That comes in handy for song airs, which often do such dipping. As I got to know the whistle I discovered that there is much more to it. First, you can play the middle c-natural with that seventh hole, like this: xxx xx(x)xx. The regular oxx ooo c-natural is also in tune (it’s an Overton), but the all-holds-barred c-natural is a bit stronger. And you can slide into the middle d from the c-natural, which is exceptionally cool if you want to freak out a someone who plays the whistle and is listening closely.
I clipped a song, She Moved Through the Fair, to demonstrate. Here is the the recording and here are the dots (vaguely):
Just kidding! Sorry, that wasn’t me on the Overton D/C Modal. Remember those little buzz things kids would hold in their palms to give you a jolt when they shake your hand? Not that it matters. Anyway, here is me playing She Moved Through the Fair (sorta) on my D/C modal. You can hear me really sliding into that second middle d, milking it a bit. She Moved… on Overton D/C modal.
That seventh hole also permits you to roll the D on a D-whistle, tapping the c-natural hole. That should suit all those fine who can’t get enough of rolling the c-natural (which is by the way also very easily done by playing an A-roll with the four fingers of your right hand down). I am just mentioning it, not recommending it, or anything. 
But wait, there’s more, and I’m not talking about the six Japanese steak knives. There is the f-natural hole. That lets you play, um, f-naturals. I like using it for the faster stuff. Great for such tunes as Julia Delaney (no need to switch whistles in a set) or My Marianne, even Give me Your Hand (if you’re so inclined). But that already shows the limitation of the f-natural hole: you can’t bend it. The advantage of half-holing is that you have total control over the pitch of the note. Incidentally, the big problem with half-holing is that you have total control over the pitch of the note. So, I find myself using both. If I want to make the f-natural expressive, which usually means pushing it noticeably sharp, I halfhole. If I just want to go on to the next note, I like the f-natural hole.
Here is another clip (came out a bit sloppy): The Maids of Mitchelstown. There is a characteristic f-natural in the second part. The tune is often played on a C-whistle to give a clear, reliable f-natural. But that is weakness. Real whistlers use a D-whistle and half-hole. Since I have moments of weakness, I’ve used the f-natural hole for the first f-natural and have half-holed the second one. The Sloppy Maids of Mitchelstown.
P.S. Edited to add that you can also use that f-natural hole for very effective rolls. Colin Goldie demonstrated that for me, but I haven’t developed the knack yet.
I have dived right in and have gone on and one about c-naturals and f-naturals. Still, that’s not the important stuff. The important point is that this is a fantastic whistle, strong, balanced, and easy to play. It is not one of Colin’s “easy-blow” whistles, and it requires the player to support his or her breath. The tone is clear and lovely and Cosmic. It’s fairly loud, but not as loud as a Susato. Gorgeous, and I’m in love all over again.
