Harmophon

The Koestler company manufactured single-action accordions and mouth organs in Graslitz until World War II. In 1946, a new plant was built in Nauheim.The company attempted to broaden its business segment by making electric instruments. The Harmophon is an electrified reed instrument with a short manual and integrated loudspeaker. The tone quality can be changed using slide controls. Koestler began selling the Harmophon in 1955 and stopped production of musical instruments in 1973 for economic reasons.