Accordion is a keyboard instrument belonging to the free-reed instrument category. The sound is produced by sound pressure which makes the steel reeds vibrate. Both polyphonic and melodic textures may be played with the instrument. The right hand panel accommodates the melody keys, while the left hand is reserved for bass keys. The bellows, which are used by pulling or pressing are placed between the two panels.

The modern accordion utilizes 41-45 piano-style keys. Other models have three parallel vertical rows of buttons tuned to thirds. A bass panel with chord function is often used in dance music. In concert music a melody bass panel capable of full chromatic melody is utilized. The tonal range of accordion can span seven octaves.

Other accordion instruments are the English concertina (hexagonal) and the Argentine bandoneon (quadrangular). The French version of the accordion is called Musette which has three slightly differently tuned voices. This tuning produces the chorus-effect characteristic of musette.

The sound of accordion is compatible with most instruments and it can also be played at very low volumes. 

Recommended combinations:

Accordion with violin or viola
Accordion with flute