Invented in 1821 by Christian Buschmann, the harmonica consists of a small casing containing a series of free reeds leading to holes on the side of the instrument. It is played by placing the instrument between the lips and inhaling or exhaling as necessary to activate appropriate reeds with the tongue being used to cover unwanted holes. Through lateral movement between the lips, the player is capable of producing, most commonly, a range of three octaves from “c1” to “c4”. Two main types of harmonicas include the diatonic and the chromatic.

The harmonica is used primarily for entertainment and folk music, however composers such as Milhaud, and Vaughan Williams have written serious pieces for the instrument. In addition, Arthur Benjamin, Malcolm Arnold and others have written full concertos for harmonica and orchestra. The harmonica also plays an important role in music education as it is very accessible with a substantial repertory of pedagogical music.