The three branches of the woodwind family have different sources of sound. Vibrations begin when air is blown across the top of an instrument, across a single reed, or across two reeds. Reeds are small pieces of cane. A single reed is clamped to a mouthpiece at the top of the instrument and vibrates against the mouthpiece when air is blown between the reed and the mouthpiece. Two reeds tied together are commonly known as a double reed. This double reed fits into a tube at the top of the instrument and vibrates when air is forced between the two reeds.
Originally made of wood, the flute is now made from silver or gold and is about 2 feet in length. It looks like a narrow tube with a row of holes covered by keys along one side. The player blows air across the small hole in the mouthpiece to produce a sound that can be either soft and mellow or high and piercing.