piano accordion

The piano accordion is a portable musical instrument characterized by a piano-style keyboard for the right hand and a bass casing, usually with buttons, attached to opposite sides of a hand-operated bellows. The invention of the piano accordion is credited to French manufacturers in the mid-19th century.12

Inside the instrument, free reeds vibrate when air from the bellows passes over them. These reeds are selectively activated by pallets controlled by the keyboard or buttons. Double-action accordions, like the piano accordion, have reeds tuned to the same note, allowing each note to be played with both the push and pull of the bellows. Some models feature couplers (registers) that activate additional sets of reeds to alter the sound, and the bass side can be highly complex, offering numerous buttons for bass notes and chords. The piano accordion is used as both a concert and folk instrument.1