Wind machine Chordophone Most instruments known as chordophones are defined as string instruments, wherein their sound is derived from the vibration of a string, but some such as these examples also fall under percussion instruments. Hammered dulcimer, Cimbalom Onavillu Piano Berimbau Jhallari Kolitong Takumbo Aerophone Most instruments known as aerophones are defined as wind instruments whereby sound is produced by a stream of air being blown through the object. However, plosive aerophones, such as the udu, are percussion instruments and may also overlap with the idiophone family. In certain situations, such as in an orchestra or wind ensemble, wind instruments, such as the Acme siren or various whistles, are played by percussionists, owing to their unconventional and simple nature. Apito or samba whistle Siren Slide whistle Udu Whistle or police whistle By musical function or orchestration When classifying instruments by function it is useful to note if a percussion instrument makes a definite pitch or indefinite pitch. For example, some percussion instruments such as the marimba and timpani produce an obvious fundamental pitch and can therefore play melody and serve harmonic functions in music. Other instruments such as crash cymbals and snare drums produce sounds with such complex overtones and a wide range of prominent frequencies that no pitch is discernible. Definite pitch of Music Percussion instruments in this group are sometimes referred to as pitched or tuned. Examples of percussion instruments with definite pitch: Chimes/Tubular bells Crotales Glass harmonica Glass harp Glockenspiel Handbells Marimba Mridangam Rototom Steelpan Tabla Timpani Tuned Triangle Vibraphone Wind chimes Xylophone Xylo-marimba Indefinite pitch Instruments in this group are sometimes referred to as non-pitched, unpitched, or untuned. Traditionally these instruments are thought of as making a sound that contains such complex frequencies that no discernible pitch can be heard. In fact many traditionally unpitched instruments, such as triangles and even cymbals, have also been produced as tuned sets. Examples of percussion instruments with indefinite pitch: Bass drum Castanets Cymbals Rainstick Slapstick or whip Snare drum Tamtam Tom-tom By prevalence in common knowledge It is difficult to define what is common knowledge but there are instruments percussionists and composers use in contemporary music that most people wouldn't consider musical instruments. It is worthwhile to try to distinguish between instruments based on their acceptance or consideration by a general audience. For example, most people would not consider an anvil, a brake drum (on a vehicle with drum