Well, perhaps I'm cherry picking here, and from what I see above, that's okay, right.

... so I would suggest the piano accordion to be a direct descendant of the harmonium; thanks to the inventive efforts of the Parisian harmonium builders Busson and M. Bouton. That said, every great instrument ought to trace its origins to antiquity...

and as the free-reed aerophone begins with the sheng, I am happy to embrace this noble Chinese instrument as our starting point. However, a special mention goes to the High Renaissance designs of Leonardo da Vinci, whose accordion was an incredible imagining of what was to transpire in the fullness of time... in the special places... Castelfidardo, Stradella, Vercelli.