A free-bass system is a system of left-hand bass buttons on an accordion, arranged to give the performer greater ability to play melodies with the left-hand and form one's own chords. The left-hand bu

Concerto for Free Bass Accordion was written for the solo free-bass system accordion by John Serry Sr. in 1964 and was revised in 1966. A transcription for solo piano was completed in 1995 and revised