Seriously, that’s what this is, more or less. Da Vinci took a hurdy gurdy and designed a huge one that goes all the way down to cello range, and set it up to be shaped like a harpsichord. He called it a “viola organista,” but it’s basically a giant hurdy gurdy.

Da Vinci never built his design, but Slawomir Zubrzycki has:

That’s… pretty awesome, actually. ^_^