May 6 is International Accordion Day sponsored by the Confédération Internaionale des Accordéonistes or the CIA. If you go to their website you will find events around the world celebrating this instrument including Vivaldi’s Four Seasons Concert performed by Nihad Hrustanbegovic, Classical Accordionist.
This image is the poster for that event.
According to Encyclopedia.com, development of the accordion is generally thought to have been inspired by the Chinese cheng, the first known instrument to use a free vibrating reed to create sound. This instrument was invented approximately 5,000 years ago. It consists of a series of bamboo pipes, a resonator box, a wind chamber, and a mouthpiece. It has a shape that resembles a phoenix and was introduced to European musicians in 1777.
The first accordions were invented in the early nineteenth century. In Germany, Christian Buschmann introduced and patented an instrument called the “Handaeoline” in 1822. It had an expandable bellows, a portable keyboard, and a series of free vibrating reeds inside. Seven years later, Cyrillus Damian refined the instrument by adding four bass keys that produced chords. He was awarded a patent for this instrument, which he called an accordion.