Melodeon

This is a specific type of single-action accordion that’s also known as a German Accordion. The simplest designs provide only a single row of buttons for the melody, but it’s interesting that the instrument plays a different pitch when the bellows are drawn and another when the bellows are pressed. Typically, melodeons are tuned to a single key, most often C. Obviously this precludes anything more than simple melodies. Older melodeons were built with brass reeds, while they are now almost always steel. On the bass side are two spoon-shaped keys, one for the bass note and another for the chord, each giving the tonic or the dominant according to the direction of the bellows. There is also an air release button for the thumb.