You will need 4-6 glasses that are the same.
Line the glasses up and fill them up with different amounts of water.
The first glass must have the most water, the second needs a little less water, etc.
Keep this going until the last glass only has a little water in it.
Using a spoon (wooden or metal) hit each of the glasses and listen to the difference in pitch.
Can you come up with a musical sequence and film yourself performing it?