Free-bass system

A free-bass system is a system of bass buttons on an accordion, arranged to give the performer greater access to playing melodies on the left-hand manual of the instrument and to forming one's own chords, by providing a buttonboard of single-note buttons with a range of three octaves or more, in contrast to the standard Stradella bass system which only allows bass notes (range of a major seventh) and preset major, minor, dominant seventh, and diminished chords. The term "free-bass system" refers to various left-hand manual systems that provide this functionality:

By the year 1900, the Stradella bass system had principally reached its current construction with 120 buttons over 6 rows. However, while that setup worked well for major and minor music accompanied by many chords, the performer would only have access to about a single octave of notes while playing - two with a timely shift of registers. The problem was solved in the early 1900s by adding three rows of chromatically ordered single notes next to the standard bass. In 1900 in Moscow Russian master Bakanov made a garmon with piano keyboards for both right and left hands. From 1906 the brothers Kiselevs' factory in Tula began to produce bayans with the three-row free-bass left keyboard.

The Hohner company decided to enlarge the market for accordions by turning the instrument from its traditional music roots into an established instrument for orchestras. An orchestra was put together, touring Germany to introduce the new concept. The company also supplied sheet music for this new type of accordion. Although these were reportedly popular, it wasn't until later when the instrument became more widespread.

In North Europe, free-bass accordionist Mogens Ellegaard helped popularize the instrument and inspire compositions for it. In an interview he describes how the free-bass accordion was still practically non-existent in his childhood (born 1935), but how composers in his native Denmark began to write works for him since 1958. In 1968 he arranged the manufacture of accordions with nothing but free-bass layouts to accommodate newcomers, as free-bass accordions would otherwise always include standard bass.

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