Tuning

As you can see from the above photo, it took a few tries to get the tuning for the overall length correct. At this stage I also tinkered with the position of the fipple block and mouthpiece cap to get the right sound. I had to sand away the top of the fipple block on an angle so that as the air passed through the mouthpiece, the top of the fipple block rose towards the mouthpiece cap. This increases the pressure of the air flow so as to strengthen the whistle's response and cut down on air requirements. This is known as the Bernouli effect.