Clickety clack. That’s all Sergei Rachmaninoff heard as he practiced his new Piano Concerto No. 3 in advance of his big American tour, during which he would debut the piece. That’s because he finished the piece just before departing for the U.S. and didn't leave himself time to practice. He had to make do with practicing on a silent keyboard on the ship. When you hear how fiendishly difficult the piece is, it makes this story even more amazing.