Circular Breathing Tutorial

Circular breathing is the art of using your cheeks to push air through the mouthpiece while inhaling through the nose. The result is an uninterrupted stream of air that can span multiple breaths. One can literally play for many minutes without stopping. In classical music written for the horn, this is an almost useless skill. A handful of jazz trumpet players have put the technique to practical use, and oboists do it regularly. Now there is a tutorial for those who aspire to learn the trick and be able to impress people in the practice room:

First try to get the idea of pushing air out of your lips using the muscles in your cheeks, rather than your lungs. Put your hands on your cheeks, then puff out your cheeks and push some air out with your hands. It'll just be a little air, but the point is that you are not using the normal breathing muscles to expel it. Using the cheek muscles to exhale is quite a different feeling. Now take your hands away and try pushing the air out with just the cheek muscles. Once you have an idea of what that feels like, the next step is to take a quick breath through your nose, so you're doing those two things at the same time. Start breathing in through your nose, and while you're doing that push the air out with your cheeks. That's the concept.

Link