Chord organ

The chord organ is a kind of home organ that typically has a single short keyboard and a set of chord buttons, enabling the musician to play a melody or lead with one hand and accompanying chords with the other, like the accordion. Tone-wise, a chord organ is almost identical to an harmonium, accordion, or similar. It was invented by Laurens Hammond in 1950 (model S-6) as an electronic home organ based on vacuum-tube circuits, similar to his earlier Novachord and Solovox models. In addition to Hammond, also Wurlitzer, Farfisa and Estey Organ made electronic chord organs.