★ ^^* 전체 화면 으로 감상 *^^ ★ Sharp handset 광고 Video 꼭 보 세요 ! In a tranquil forest , a single wooden ball rolls down a stepped wooden ramp , continuously , for 3 minutes . At each step , it falls and strikes a wooden bar tuned to play a single note of the 10 th movement of Bach ’ s Herz und Mund und Tat und Leben , BWV 147 , commonly known by its English title , Jesu , Joy of Man ’ s Desiring .