From the audience, this instrument looks like a typical grand piano. Then the maestro takes his seat and begins to play. It's a sound nobody has heard before, because this instrument, designed by Leonardo Da Vinci five centuries ago, has just been built for the very first time. And it sounds heavenly.

The viola organista was invented by da Vinci with characteristics of a harpsichord, an organ and a cello. In the place of a piano's felt hammers, spinning wheels draw across the strings like a violinist's bow. The player operates a foot pedal to spin the wheels, playing notes on a keyboard identical to a piano's. But the sound, sinewy like a stringed instrument but with a piano's direct, well-defined tones, defies comparison to traditional instruments. This short video has some nice close-up shots of the mechanism at work:

Polish concert pianist and instrument maker Slawomir Zubrzycki built the viola organista from sketches and notes in da Vinci's voluminous manuscripts. The process took 5,000 hours spread across three years.

Listen to Da Vinci's Genius Piano-Cello Played for the Very First Time

Zubrzycki's debut performance on the instrument, at the Academy of Music in Krakow, Poland, is the first time an audience of any size has heard the instrument — while the design dates back more than 500 years, there is no historical account of it ever having been built. The sinewy, flowing sound that the master himself never heard makes even the most staid classical music exciting. Just listen to it. It'll bring a Mona Lisa smile to your face. [The Age]