The melodica, also known as the pianica, blow-organ, key harmonica, free-reed clarinet, or melodyhorn, 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 is usually two or three octaves long. 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.