5 drinking glasses
Arrange the glasses next to each other and fill them with different amounts of water. There should be different amounts of water in all the glasses.
Hit the glass with the least amount of water and observe the sound. Then hit the glass with the most water.
Hit the other glasses and see what noise they make. See if you can create a tune by hitting the glasses in a certain order.
How does this work?
Each of the glass will make a different tone when hit with a pencil. The glass with the most water will have the lowest tone, while the glass with the least water will have the highest. Small vibrations are made when the glass is hit. This creates sound waves which travel through the water. More water means slower vibrations and deeper tone.