How Does the Diatonic Harmonica Work?
Structure of a Harmonica The unique sound of a harmonica, also called mouth harp or mouth organ, comes from its interior design, which is a series of plates. Directly inside each of the outer covers is a thin metal plate of reeds, the top one called the blow reeds since they sound when air is blown into the harmonica, and the bottom plate called the draw reeds because they sounds when air is drawn in through the harmonica. The reeds themselves do not produce notes through their vibration, rather they change the shape and size of the air passageway such that a note is produced. On each plate are slots of different length on which reeds of increasing size are attached at one end. Between the two reed plates is a thicker comb made of plastic, metal or wood, and which contains the actual chambers through which air passes into and out of the instrument and past the reeds. Diatonic Harmonicas Diatonic refers to the intervals between the notes of the white keys on a piano. In other words, a p
