Yamaha C5X grand pianoIntroducing the Yamaha C5X grand piano The C5 has always been an excellent smaller concert instrument. With the latest update the piano has become a much cleaner, resonant sounding piano. A really significant upgrade to the C3X, the C5X is a full 6'' larger which makes a huge different to the soundboard area as well as string length. With the new upgraded string material and improved soundboard design the C5X is a wonderful larger domestic piano or