So there I was, listening to a visiting choir, when somebody started playing a whistle. At least it sounded like a whistle, playing a melody line that complimented the piece being sung. Why is this significant?
Nobody had a whistle.
The technique that was being demonstrated is Polyphonic Overtone Singing. The “Poly” part refers to singing two notes at the same time. Yeah, with the same mouth. It’s an amazing sound, believed to have originated in Mongolia a zillion years ago. It’s actually pretty simple to get a two-note noise, but controlling it? Many moons of practice.
So here’s how it works, give it a shot. You might want to do it while you’re alone because you’re going to make some silly faces and noises and you don’t want someone to think you’ve lost your marbles.
First, curve the sides of your tongue up against your teeth. It should feel like there’s a nice, airtight seal. Now make an opening by lowering the tip of your tongue. This becomes the whistle that isn’t there. Try singing a comfortable note with an “errrr” so it resonates in your chest and then let some of the air sneak out the whistle you just made with your tongue. Voila; two notes. Sliding the tip of the tongue around and changing the shape your lips are making can move the whistling notes around, feel free to tinker with it to see what you get. (This would be the “looking silly” part I mentioned.)
If you spend a zillion years practicing, you’ll sound like this: https://youtu.be/vC9Qh709gas