French 3 3 bass layout - not quite...

[KiwiSqueezer]

I am puzzled by a B-system CBA I have seen recently. Its 120 bass buttons are arranged with 3 rows of fundamental notes, and 3 rows of chords (no dim 7ths). I've discovered a little about the 'French 3 3' layout, where, for example, the 'C' column goes Ab, E, C, CM, Cm, C7, but this one goes Eb, E, C, CM, Cm, C7. In the apparently 'conventional' French layout, the first row's Eb would be on the adjacent 'G' column, whereas this box has Bb. Thus, comparing the two layouts, the row nearest the bellows is effectively shifted by one button. This accordion's layout is otherwise conventional Stradella.

Searching old posts shows that Paul De Bra considers that this accordion's 'shifted French' layout is familiar to him, whereas what I have called the 'conventional' '3 3' layout isn't.

I'm no music theorist, and fairly new to accordions - there's so much to learn! Please can anyone explain why there may be (at least?) two variants of the 'French 3 3' bass layout? Is it a regional preference? This box was probably bought new in Gelderland, Holland. Are there good musical or ergonomic reasons for the 'shifted' variant? Any thoughts welcome!

 

[dunlustin]

the 'C' column goes Ab, E, C, CM, Cm, C7 : The Ab gives the minor third for the adjacent 'F' row

this one goes Eb, E, C, CM, Cm, C7: The Eb gives the minor third for the 'C' row

Difference? Which is easier to reach I guess --potato/potahto?

By the way, the F7 offers a work-around for the absence of the Cdim and so on up the keyboard
( F7: no root then A C Eb )

 

[debra]

...

Searching old posts shows that Paul De Bra considers that this accordion's 'shifted French' layout is familiar to him, whereas what I have called the 'conventional' '3 3' layout isn't.

...

Indeed, The layout that has Eb, E, C, CM, Cm, C7 is what I have seen on all 3+3 accordions I have ever encountered (including an early 70's Crucianelli Super Video I still own).
And I just happen to have a Scandalli here (for tuning) with 3+3 Belgian bass system and it too has Eb, E, C on the same column.

 

[TimeSwan]

I've only seen a handful of 3+3's and only one of them had the Ab, E, C bass layout, the rest have been Eb, E, C.

Your guess about it being a regional difference is as good a guess as any I could come up with.

 

[Henry D]

My Crucianelli Piermaria Nazzareno circa 1955 is a C griff French bass CBA with the offset (C E Ab) set up for the LH.

Really not worth writing home about but perhaps slightly more accessible (for me) when running on the LH root notes.

On the 20's 30's 140 bass setups, the minor counterbass row seems most common based upon what has come my way, but the augmented seventh as a fifth chord row instead of the flatted third top counterbass row seems to run it a close second. My Excelsior four rocker from the early thirties has 160 bases and covers all the bases! (minor third, third, root, minor chord, major chord, seventh, diminished, augmented)

Though I might be able to adjust it- a side effect seems to be a relatively heavy action on the bass buttons. It's clean, and I'm leery of tinkering with the 90 odd year old springs. That and my bass button stand only takes 120 bass pistons...