Here is what you will need: Glasses, water, food coloring, spoon.
1. Fill your glasses with different amounts of water.
2. Put several drops of food coloring into each glass.
3. Using the back of the spoon have your children gently tap the top of each glass.
4. Have your children "play" different songs, like "Twinkle, Twinkle" or "Jingle Bells".