They can have a single membrane, or one at either end. The family of chordophones includes instruments whose one or more strings, stretched between fixed points, vibrate when they are plucked, struck or rubbed. The primary vibrating agent of the family of aerophones is air itself. It is generally contained in a tube, as is the case for flutes and trumpets. Cymbals and bells are two examples.
Percussion instruments form a highly varied family.
Instruments that are shaken, like rattles . Instruments that are struck, which make up the largest group. Instruments consisting in a pair of similar elements that are struck together, like the Moroccan castanets or the Egyptian finger cymbals. Clappers are also part of this family. Wooden spoons and bones, from Canada, the sahn sua, from Vietnam, the badine, from Madagascar.