The History of the Accordion
The accordion was invented in the early 1800s in Europe drawing from the concept of older Chinese instruments and only taking shape in its modern form later in that century – The sheng. It is in fact the first known instrument to use the free vibrating reed principle, which is the basis of the accordion’s sound production. The Sheng attracted the attention of European musicians and craftsmen after being taken to Russia around the year 1770. Assertions that this marked the introduction of the free-vibrating reed principle in Europe are debatable. Among the earlier variations on this design in the West was the portative, which was widely heard in England during the 12th and 13th centuries

The portative consisted of a small keyboard, bellows, and reed pipes, and was strapped onto the player:

  • 1822 – F. Buschmann invented small portable keyboard, with free vibrating reeds inside the instrument itself, He dubbed it the hand-aeoline
  • 1829 – Cyrillus Damian, a Viennese instrument make design featured two to four bass keys that produced chords within a range of an octave
  • 1829 – Sir Charles Wheatstone was awarded the British Patent No. 5803 for his concertina
  • 1832 – The first music book featuring both music and arrangements was written by A. Reisner
  • 1850 – The chromatic accordion, which produced the same note on the press and the draw of the bellows
  • 1877 – Schrammel accordion had 52 treble buttons arranged in three rows that produced the same notes

The modern accordion has three primary sections, the expandable bellows and the two wooden end units called the treble and bass ends. The treble end of the accordion has a keyboard attached. The bass end contains finger buttons that play bass notes and chords. The reeds and electronic components are located on the inside of the bellows. The accordion is called a free reed instrument because it uses free-standing reeds to produce sound, similar to the harmonica. The reeds are made up of metal strips that are riveted to either side of a rectangular metal plate.  When air passes through this slot in the appropriate direction the reed vibrates, producing the characteristic accordion sound. There are three main styles of accordion: diatonic, chromatic and keyboard. One of recent invention is an accordion attachment that allows the musician to modify notes by bending the tone

The keyboard on the right side of the accordion typically contains 41 keys but the smaller models can contain as few as 25. The full concert accordion will typically have four sets of reeds called treble shifts, one set tuned  in unison, a second set tuned  one octave higher, a third tuned one octave lower, and the fourth set, the tremulant, tuned slightly higher than unison
The accordion is capable of a large dynamic range from very soft to very loud. Loud dynamic levels with several notes and full chords sounding require more air and cannot sustain the notes for more than a few seconds. Softer dynamic levels with fewer notes depressed can be sustained longer. No volume control, it’s directly related to the vigor you put into performance

wikipedia – Glossary of Musical Terminology,,, www.cavitas-air.comm

according – project stamps 2003-2028