Instruments from the Five Classes
Idiophones
Idiophones are sometimes defined by what they are not: an idiophone does not have an air column to be set in motion directly, nor does it have a membrane or strings to set the air in motion. In general, idiophones are solid or hollow bodies with sonorous capabilities.
Membranophones
Membranophones are "drums," vessels or frames with a membrane stretched over an opening. They are subdivided according to how they are played: struck, shaken, or friction. A fourth type, called sympathetic, only modifies another sound by vibrating in sympathy with it.
Chordophones
Chordophones are instruments with a string or strings stretched over the body. To produce a sound, the strings are plucked, bowed, or struck. However, for classification, they are subdivided according to their body shape and string alignment.
Aerophones
Aerophones are instruments that are blown, whether in person or mechanically, to produce a sound. This includes the flutes, reeds, and brass of the orchestra, plus the organ, accordion, and several others, such as the bull roarer, a plaque moved through the air to produce a sound.
Electrophones
Electrophones use electricity to produce or reproduce sounds. The first was Elisha Gray's 1874 electro-acoustic musical telegraph that set metal reeds in motion with electromagnets. Most electrophones today are electronic, producing oscillations through their circuitry alone.
