Woodwind instruments are a family of musical instruments within the more general category of wind instruments. There are two main types of woodwind instruments: flutes and reed instruments (otherwise called reed pipes). What differentiates these instruments from other wind instruments is the way in which they produce their sound. All woodwinds produce sound by splitting an exhaled air stream on a sharp edge, such as a reed or a fipple. A woodwind may be made of any material, not just wood. Common examples include brass, silver, and cane, as well as other metals including gold and platinum. Examples are a saxophone, a bassoon and a piccolo.