Hi Tony,
It's not clear exactly what you want to do. Do you mean you want to use the same relative key positions as a major scale, but to play a minor scale? If so, you need to change a major scale layout tablature set to minor.
You can find the Hohner Corona 3 row layouts at melodeon.net.
Look at one of the major key layouts, such as G/C/F (set up to play easily in the key of C major. You could change each major scale note to a corresponding minor scale.
For example, to make Am scale, change all Cs to As, Ds to Bs, Es to Cs, etc.
You could do the same with the notes on your organetto, which may or may not match the Hohner 3 row. You may only need to program the keys on your organetto, not all 3 rows.
I have not seen such a layout on the internet but it wouldn't be hard to do. Then it looks like you have to download a tablature making software to make the sets. Or find some from someone. I don't have this instrument so I don't know if you can make bass notes and chords in all minor keys.
Or, you could do like the TexMex guys and play in minor "cross keys," ie, Am on a C layout.
Maybe someone with this instrument can explain it better. Btw, what minor key do you want to play in?
Hope this makes sense
