To make a sound on a woodwind instrument we blow through a mouthpiece or reed. The Clarinet uses a mouthpiece with a single reed  (a flat thin piece of bamboo) that vibrates and produce the sound! The Bassoon and Oboe use double reeds, which are made of two reeds attached together at the base.  Flutes are the exception to the reed rule and are played by blowing across an opening at the end of the flute.