The melodica is a free-reed instrument similar to the pump organ and harmonica. It has a musical keyboard on top, and is played by blowing air through a mouthpiece that fits into a hole in the side of the instrument. Pressing a key opens a hole, allowing air to flow through a reed. The keyboard covers usually two or three octaves. Melodicas are small, light, and portable. They are popular in music education, especially in Asia.
The modern form of the instrument was invented by Hohner in the 1950s, though similar instruments have been known in Italy since the 19th century.
The melodica was first used as a serious musical instrument in the 1960s by composers such as Steve Reich, in his piece titled Melodica (1966). Brazilian multi-instrumentalist Hermeto Pascoal developed a technique consisting of singing while playing the melodica, resulting in a wide tonal and harmonic palette. It is associated with Jamaicandub and reggae musician Augustus Pablo who popularized it in the 1970s.
Electronic melodica (Hohner Electra-melodica) is a kind of electronic musical instrument, which has no reed but mouse piece of Wind controller. Audio signal is sent to internal or external speaker or headphones, and can be played without making environmental sound. Has not been commercially supplied.
Layout of a melodica keyboard with three octaves (36 keys)
Hohner Melodica Soprano: right side, keyboard and bottom views
Melodicas are classified primarily by the range of the instrument. Melodicas with different ranges have slightly different shapes.
Soprano and alto melodicas are higher-pitched and thinner sounding than tenors. Some are designed to be played with both hands at once: the left hand plays the black keys, and the right hand plays the white keys. Others are played like the tenor melodica.
Tenor melodicas are a lower-pitched type of melodica. The left hand holds a handle on the bottom, and the right hand plays the keyboard. Tenor melodicas can be played with two hands by inserting a tube into the mouthpiece hole and placing the melodica on a flat surface.
Bass melodicas also exist, but are less common than other tenor, alto, and soprano.
The Accordina, generally made of metal, uses the same mechanism as a traditional melodica. The keyboard is replaced with a button arrangement similar to a chromatic button accordion's keyboard.
Although the majority of melodicas are made of plastic, some are made primarily of wood. The Sound Electra corporation makes the MyLodica, a wooden melodica designed "...to produce a warmer richer sound than that of its plastic relatives." The Victoria Accordion company in Castelfidardo, Italy, produces a range of wooden melodicas and accordinas that they market under the name Vibrandoneon.