^ I'm not "listening" to this but thought it was a neat video that demonstrates circular breathing. For anyone unfamiliar, it's the process of how wind and brass players have developed the difficult technique of sustaining an endless breath/note. it takes a lot of practice and skill to execute. It's the process of breathing through the nose to get fresh air in your lungs as you are still blowing air into the mouthpiece/pipe of the instrument to produce a wind stream which of course produces sound in the instrument.