The brilliant Leonardo Da Vinci designed many devices - he created the first plans for tanks and helicopters, designed devices for chemistry and engineering, and also - musical devices.
500 years ago, Da Vinci made plans for the 'Viola Organista', an instrument that combines the keyboard of a piano with the sound production mechanism of string instruments such as the cello or the violin.
Now, half a millennium later, the viola organista has been actually built, following the old genius's schematics. Hear the unearthly sound of a one-of-a-kind musical instrument. If you're a music lover, you're in for a treat - a new musical instrument that sounds like nothing else.
When playing, the organist generates sound by bringing steel strings into contact not with quick-acting padded hammers (as with a traditional piano), but with spinning, horse-hair-lined wheels that the player keeps in motion via a foot pump. When a key is pressed, the string touches the wheel-bows, producing the note. (You can see this about 4 minutes into the video below.)