One half of circle: Place the palm of your hand in front of your mouth and keep it moving in a circular motion while hissing.The second half of the circle: Starting a couple of seconds after the first half, the rest of the circle whistles down the scale. (Doh, Te, La, So, Fah, Me, Ray, Doh.)When the whistlers get to the bottom of the scale, everybody responds with a well-rounded BOOM! Repeat all but BOOM twice, repeat all but BOOM three times.