The Collapsing Chamber
As you proceed through the counterclockwise motion of the chart, use chamber size in the mouth to change the tone. You will also see that as you decrease the size of the mouth chamber the reed creating the vibration moves from the lips to the tongue. This is a very important detail often missed in teaching basic circular breathing.
Starting Out Softly
Beginners often find themselves blowing too hard. Make an effort to breath as lightly as you can while maintaining the drone. This is an exercise in control and will greatly improve your range. There is always a time for loud and intense playing. But when starting out, even the masters start quietly and softly. This building in intensity will create an energy that is the very reason didge players find the instrument so exciting.
Breath: It's All About the Diaphragm
Push the stomach muscles out to inhale and pull the same muscles in to exhale. This puts physical distance between the breath and the vigorous activity of the face, mouth, and throat. This increases the volume of air drawn into the lungs with short quick sniffs of air taken in the nose. Don’t breathe from the chest. That is a much weaker muscle group and is more sensitive to that vigorous activity.
Learn to play higher and higher tones. The greater the distance between the highest and the lowest tone, the more time available for sniffing air through the nose during the snap back phase of the process. Don’t try to circular breathe at the end of your breath. Try to complete the cycle in the first third to one half of your breath capacity.
To play the high tones the mouth chamber size needs to be small and the tongue should touch the back of the lower front teeth. You will feel the vibration role off the tongue and the lips. To drop the tone down, the tongue starts to move back slowly from the teeth making the chamber size larger. You can continue enlarging the mouth chamber size by letting the cheeks inflate. Hold the tone through the entire movement. Then quickly evacuate the air by manually squeezing air out with the cheek and the tongue action. The tongue acts like a wall pushing air and vibration back to a small chamber.