a music bell striking snowflakes in a crystal ball includes an upper rotary mechanism , a lower rotary mechanism and a crystal ball . the music bell rotates not only a gear ring tray of the lower rotary mechanism on the bottom portion and a doll disposed on a rotary tray of the upper rotary mechanism , but also a magnet gear inside the crystal ball to cause water flow therein according to the principle of magnetic repulsion , so as to create a beautiful and dynamic scene of floating snowflakes .