Leonardo da Vinci's viola returns from the dead REFILING VIDEO WITH TEXT STORY:With elegant black and tan keys it looks like a baby grand piano, but when tinkled they release the voluptuous tones of a cello. Painter of the Mona Lisa, Italian Renaissance genius Leonardo da Vinci also dreamt up the Viola Organista in the late 15th century as a marriage of keyboard and string instruments. But he never built it, experts say. Virtually forgotten, it has come to life thanks to a Polish concert pianist with a flair for instrument-making. Images and soundbites