Multi-row Systems
A one-row DBA has the advantages of being light and compact, but is by its nature limited to the notes of a single diatonic scale. Since the mid-to-late 19th century, instruments have been produced with more than one row in order to give players a greater choice of scales and tonalities.
Multi-row systems can be divided into two broad classes: "fourth-apart" systems and "semitone-apart" systems.
Read more about this topic: Diatonic Button Accordion
Famous quotes containing the word systems:
“No civilization ... would ever have been possible without a framework of stability, to provide the wherein for the flux of change. Foremost among the stabilizing factors, more enduring than customs, manners and traditions, are the legal systems that regulate our life in the world and our daily affairs with each other.”
—Hannah Arendt (1906–1975)