A whistle or call is a simple aerophone, an instrument which produces sound from a stream of forced air. It may be mouth-operated, or powered by air pressure, steam, or other means. Whistles vary in size from a small slide whistle or nose flute type to a large multi-piped church organ.
History
The whistle has its roots dating back to ancient China, where night watchmen would blow into the tops of acorns to alert the towns to invading Mongolians.
In ancient Egypt two blades of the papyrus plant along the Nile river were held together in between the palms. By blowing into the palms the papyrus leaves would make a loud vibrant sound.
Types of whistle
Many types exist, small mouth blown whistles for various functions from toys to hunting using bird and fowl calls type whistles, to professional whistles as police, boatswain’s pipe, military, sports whistles (also called pea whistles), to much larger steam or air preasure operated ones as train whistles, which are steam whistles specifically designed for use on locomotives and ships.
Although almost all whistles have some musical character, common whistles are not usually considered musical instruments, since they cannot play a melody, unless used as a – very shrill and loud – noise and rhythm instrument.
However, musical whistles exist, including various 2-octave musical instruments known as tin whistles (sometimes called pennywhistles or low whistles), as well as the calliope (an array of separately actuable steam whistles), organ pipes and the recorder.
Pea whistles are used in jazz and Latin music for rhythm, much as a percussion instrument is; children often use them as a toy music instrument.
There is also a more diverse type of whistle used for giving commands to sheepdogs at work, which can emit almost any tone the shepherd wishes, in order to signal different commands. This whistle is known as a shepherd’s whistle.