Which part produces sound in accordion?

The Accordion is a portable, freely vibrating reed instrument. It consists of a keyboard and bass casing that are connected by a collapsible bellows. Within the instrument are metal reeds, which create sound when air, generated by the movement of the bellows, flows around them and causes them to vibrate. The accordion is constructed from hundreds of pieces, and much of it is hand assembled. First constructed in the early nineteenth century, the accordion continues to evolve into an ever more versatile instrument.