It's time for a blast from the past:
That is the Viola Organista, a 15th century instrument designed by that ultimate Renaissance man, Leonardo da Vinci. What you can't see is that this music is issuing from what appears to be a piano.
The man playing it is Polish musician Slawomir Zubrzycki. He built the instrument from plans found in da Vinci's notebooks and debuted it at the Academy of Music in Krakow, Poland.
The Viola Organista resembles a grand piano with a keyboard. It has sixty-one strings inside but instead of hammers that strike them, the keys control four spinning wheels wrapped in horsehair. Their movements act like a bow on a cello string, creating the rich sounds you hear, similar to full string ensemble.