It is the layout of these 'chord buttons' that is so interesting as they are not placed next to each other according to any 'scale', but are set up according to the Circle of Fifths. For those of you who play from chords, any group of three adjacent chords in this Circle of Fifths are the 'basic' chords for the key in the middle. Eg. F, C and G are the basic chords for playing in the key of C.
So to arrange the chord buttons on a piano accordion in this fashion would mean that you wouldn't have to 'jump' too far to play the chords you need.
DonW has played a piece with 'piano accordion' on his AR 100 organ, Under Paris Skies.
Do a right-click to open this up an a New Tab
viewtopic.php?f=2&t=5959
This is what it would sound like played on a 'real' Piano Accordion:
Don tells me that there is one tune that was specifically composed with the arrangement of piano accordion buttons in mind.
Hugh