The
harmonica, also French harp, and
mouth organ, is a
free reed wind instrument used worldwide in many musical genres, notably in
blues,
American folk music,
classical music,
jazz,
country, and
rock and roll. There are many types of harmonica, including diatonic, chromatic, tremolo, octave, orchestral, and bass versions. A harmonica is played by using the mouth (lips and tongue) to direct air into and out of one or more holes along a mouthpiece. Behind the holes are chambers containing at least one
reed. A harmonica reed is a flat elongated spring typically made of
brass,
stainless steel, or
bronze, which is secured at one end over a slot that serves as an airway. When the free end is made to vibrate by the player's air, it alternately blocks and unblocks the airway to produce sound.