What are people's preferred left hand bass layout? (Creating a device)

[Withing]

Hello all. I'm creating a midi controller that currently replicates the right hand of a CBA accordion.

So far it's working well, but I'm wondering about creating presets to be able to also flip it around and use it as a crude emulation of the left hand too (layout is obviously a bit different than usual)

I'm wondering what people might prefer for a left hand bass system in something like this? I have 5 rows and an obvious easy option is to include what I understand to be the "free-bass" system where it's simply a mirror of the right hand. But what might you or the general public prefer? Would the "quint" system or the usual system used on converter accordions be good to have/better? Or are preferences so wide that all of them are almost equal?

I very much appreciate feedback on this. Thanks!

 

[Walker]

There is a lot to be said for Quint (fifths) system, and it is my favourite free bass accordion layout because it is based on the design and logic of the traditional Stradella bass (single note) layout - but extended to 3 parallel octaves (or more).

On smaller Quint free bass accordions (with 96 or 120 bass) there are 6 rows of basses;

Rows 1 & 2 (1st position), C2 - B2, known as the 'Great Octave'
Rows 3 & 4 (2nd position) C3 - B3, known as the 'Small Octave'
Rows 5 & 6 (3rd position) C4 - B4, known as the 'Line 1 Octave'.

Note: Concert accordions with Quint system have 160 bass buttons (8 rows) to give an added 'pedal' octave: C1 to B1, known as the 'Contra Octave'.

However, Quint system is not related to the right hand design of a chromatic button accordion. In fact, Quint system is widely associated with the piano accordion rather than the button accordion, though there are a few notable exceptions - such as Richard Galliano's button accordion.

@Withing, if you are looking for a free bass design that is compatible with a 5 row template, then it doesn't seem to me that Quint would be suitable, as it requires 6 rows of basses. Therefore, you may wish to consider one of the 'minor third' free bass systems (C, B, Bayan, Finnish) as these systems are fundamentally based on the chromatic button accordion treble design.