G'day,

Dazbo:

I'm surprised that Foolestroupe (definitely the local piano accordion guru ...) didn't point out that the 120 bass gives 20 "starting points" ... and there are only 12 keys (scales) ... each, of course, having many different modes. I would presume that this means there is an "overlap" of 8 keys ... keys that occur at each both the top and bottom of the bass keyboard.

They don't have extra reeds ... just 'links' so that they can be placed in either position. This means you can transfer any bass pattern vertically without having to nip back to the top (or bottom) to complete the accompaniment.

Rowan: The "free bass" layout can exist as the sole bass end of some (very) specialist accordions ... or as another 3 rows of (~)20 single bass notes ... arranged as a mirror image of the central keyboard of a Continental Chromatic Accordion (or "chromatica"). These allow playing of single bass notes ... or selected groups of them in order to play written accompaniments ... not the 'Stradella Bass' system's arrangement of the most useful chords for popular music.

Regard(les)s,

Bob