Via hyperallergic.com:

Slawomir Zubrzycki spent from 2009 to 2012 reconstructing Leonardo’s viola organista based on an illustration in the Codex Atlanticus, a 12-volume collection of the artist and inventor’s ideas on topics that range from botany to weapons to music. As the Sydney Morning Herald reported, the instrument appears much like a piano, but its mechanics are quite different, which is why you might look twice if you see someone playing what seems like a standard piano while the sounds are that of a stringed instrument.

The flat bed of its interior is lined with golden spruce. Sixty-one gleaming steel strings run across it, similar to the inside of a baby grand. Each one is connected to the keyboard complete with smaller black keys for sharp and flat notes. But unlike a piano, it has no hammered dulcimers.Instead, there are four spinning wheels wrapped in horse tail hair, like violin bows. To turn them, Zubrzycki pumps a peddle below the keyboard connected to a crankshaft.

As he tinkles the keys, they press the strings down onto the wheels emitting rich, sonorous tones reminiscent of a cello, an organ and even an accordion. The effect is a sound that da Vinci dreamt of, but never heard; there are no historical records suggesting he or anyone else of his time built the instrument he designed.

Hear Zubrzycki perform on the Viola Organista in the embedded video below:

An interview with Slawomir Zubrzycki can be viewed at thisiscolossal.com