This technic allows to have a continuous blowing without interruption. Althought it's not possible to breathe in and out at the same time, it's possible to blow by the mouth. This technic is very développed in the didgeridoo instrument ( visit http://www.charly-didgeridoo.com for more information) and can be used for saxophones.
For learning the circular breathing I advise you training with a straw.
At the first stage, take a glass water and a straw. Blow into the straw softly, try to keep the pression in your mouth constant (the mouth is full of air). When you want to breathe, press on yours cheeks, and at the same time take air with your nose.After this, you blow normally, this is a circular breathing cycle. Have a look to the illustration below. When you got it with the straw, try on the sax. The difficult is increasing because you have the mouthpiece into the mouth and you must make a sound. But the mecanism is the same.
It takes 3 days to understand the circular breathing with the straw. But many years is necessary to have a perfect control of the circular breathing.
In real time
Steps of the circular breathing
Blow normally with your lunges, keep your cheek full of air( red arrows ), keep cheeks full of air.
block your glottis (as you was in apnoea) and eject the air keeped in yours cheeks (symbolize by the orange circle).
At the same time pump air by your noze ( blue arrows). Yes it's possible!!, Everybody can do it.
Relax your glottis, and blow again with your lunges, Come back to the step 1. It's the most difficult step.
Now you know how to do it, just keep trying and itwill come naturally...
