The chromatic accordion was created in the 1850's by F. Walter, when he rearranged the reeds of a three row diatonic. It could play a 46 note chromatic scale. The chromatic button accordion is not diatonic, and probably has the greatest range of treble notes of any accordion available today. Their size ranges from an accordion with 20 treble keys and 12 bass buttons, to the modern chromatic button accordions which have up to 6 rows of treble buttons and 160 bass buttons.
The chromatic accordion is probably most widely used in Russia. There it is called the Bayan, and the piano accordion is called just the accordion.
Because of its cost and size, it was rejected by most conjunto musicians. Paulino Bernal was the exception, and ushered in a new era with his chromatic accordion and would become one of the most influential conjunto musicians in history.
