The mouthpiece with a simple leaf is shaped like a duck's bill and open at the bottom. This opening is almost closed by the reed. When blown on, the leaf starts to vibrate, which is how the sound is created. The player influences the pitch through the application and pressure of the lower lip, the pressure of the air column, through a corresponding widening (similar to normal yawning) or narrowing of the pharynx and the valve position of the instrument. To attach the reed to the path of the mouthpiece, the reed is clamped under a metal or plastic clamp called a "ligature". The reed can be freely positioned in the longitudinal direction, so that it is either flush with the pointed end of the mouthpiece path (the normal case), protrudes slightly or is a little shorter. Basically, it is easier to blow an instrument if the reed protrudes a little. The mouthpiece is placed in the mouth with the blade facing down, the incisors pressing directly on the top of the mouthpiece. So that the latter is not chewed through too quickly, a "bite plate" is often sticked to the top.