The left thumb is placed at a diagonal angle across the tone hole so that it may also access the register key. The little fingers remain over their respective plateau keys. The fingers are naturally curved. The upper teeth are placed on top of the mouthpiece approximately a half inch from the tip of the mouthpiece. The lip supports the reed and mouthpiece inwardly in all directions with equal pressure.
Pressure is provided by the lip muscles.
Chin muscles are firm and flat. The ancestor of the clarinet is the ancient chalumeau , a primitive reed instrument made of cane. It was a favorite instrument of the Greeks and Persians during the Middle Ages. J. C. Denner of Saxony is usually given credit for inventing the clarinet in 1690. The invention, however, consisted primarily of a speaker key.