A snow globe is a transparent sphere usually made of glass enclosing a miniaturized scene of some sort, often together with a model of a landscape. The sphere also encloses the water in the globe; the water serves as the medium through which the "snow" falls. To activate the snow, the globe is physically shaken to churn up the white particles. The globe is then placed back in its position and the flakes fall down slowly through the water. Today's snow globes sometimes have a built-in music box that plays a Christmas carol