I suspect he might actually be using his mouth though. What do you guys think? his mouth is shut all the while and if you really look at it carefully, you can see his lips move slightly. I'm not sure, I might be imagining it.!
haha, dont think so, he already wrote in the comments that it was very painful, maybe he is just bearing with the pain thats why his mouth is shut, btw he has a mic attached at the back of the hand..
Watching very carefully. his technique seems consistent. Can see a bit of vibrato too. He seems to be using his fingers at the top to let out air, almost like in a flute, clarinet or recorder.