MELODY (FREE) BASS DIAGRAM

There are several different melody (free) bass systems with different arrangements and different number of rows.
The system in the picture has the standard Stradella bass arrangement plus another three rows with bass buttons arranged chromatically (C system).
The Converter arrangement makes it possible to switch between either the Stradella arrangement with two bass rows and four chord rows or converting the chord buttons to another four rows of bass buttons.
There are also systems that has bass rows only (e.g. three rows).