A beating-reed instrument is an instrument that produces sound by the vibration of a reed. Synonyms for this type of instrument include woodwind instruments, wind instruments, reed instruments, and wind-blown instruments. Woodwind instruments are named so because they were traditionally made of wood, but now some are made of metal or other materials. Wind instruments are so called because they are played by blowing air into them. Reed instruments are types of woodwind instruments that use a reed to produce sound, while wind-blown instruments include all the instruments that are played by blowing air into them, such as brass instruments.