Savart's wheel: Toothed wheel and cardboard or air jet.

Savart's wheel: Savart's wheel is much like a gyro with teeth around the rim. It can be set to spinning with a string,- and the card is pressed against the metal teeth to make a sound of a certain frequency. OR,- an air hose can spin the wheel by blowing against the teeth, generating a sound whose frequency depends on the force of the air.