Original: To produce sound , the player closes the top end of the pipe with the flesh between his chin and lower lip , and blows a stream of air downward , along the axis of the pipe , over an elliptical notch cut into the end .
Simplified: To make a sound , the player closes the top end of the pipe with the flesh between his chin and lower lip , and blows a stream of air downward , over a notch cut into the end .