Most accordions have a dedicated bass section for the left hand. There are two primary mechanical systems used to play these notes: Bass Accordions
This report covers the two ways "bass accordions" are defined: the standard found on almost all accordions and the specialized, rare "Bass Accordion" instrument used primarily in orchestras. 1. The Left-Hand Bass Systems
Typically include "Counter-bass" (major thirds), "Fundamental bass" (root notes), and then columns for Major, Minor, Dominant 7th, and Diminished chords . Most accordions have a dedicated bass section for
Accordions are categorized by the number of bass buttons they possess, which determines their musical range and weight.
High-end professional accordions often feature a "converter" switch that toggles the left-hand buttons between Stradella (chords) and Free Bass (melodies) modes. 2. Specialized "Bass Accordions" "Fundamental bass" (root notes)