If someone is wondered what have in common mathematics and music, I invite to them to see this video of the Concert for two pianos in A BMW 1061, of Juan Sebastian Bach, played by Iliana Ross and Marekhi Kotetishvili. If you prefer something romantic, see here its interpretation of Astor Piazzola's Gran Tango. And if you wish listen to them live, write them at rossiliana(at)yahoo.es