The buttons on an accordion are usually chords, right? Is it the root then which is arranged in a circle of fifths? Or I guess if it's the same chord shape it's all of the notes in the cord too?
It seems similar to speaking? Sometimes people will talk about saying something "breathlessly."
The bass and chord buttons on a Stradella bass (the most common kind) both go in a circle of fifths, so the root and major chord are next to each other, for example. There is a second bass row with the major third, and for French accordions sometimes a third bass row.
The following rows in the column are usually a minor, major, minute 7th, major 7th, then sometimes augmented or diminished or MM7.
The root note on the 2nd row is arranged in a circle of 5ths, usually the middle corresponds to middle C (denoted by an indentation)
This is my experience with the LHS of piano keyboards.