The Bayan

The adjacent photo shows, on the left, a typical five row, 120 bass bayan. On the right is an accordion. Both instruments are used in the orchestra.
The bayan (named after a legendary Russian folk singer) was created in Russia at the end of 19th century. It could play a 46 note chromatic scale and probably has the greatest range of treble notes of any accordion available today. The size of Bayans range from 20 treble keys and 12 bass buttons, to the modern Chromatic Button Accordions which has up to 6 rows of treble buttons and 160 bass buttons. There is a large body of original Russian bayan scores, ranging from virtuoso arrangements of folk songs to serious classical and contemporary works.

 
Bayan Accordion