Cup String Instruments
Learn about sympathetic vibration by making your own string instrument.
What you need
- 3 pieces of string, each 4 feet long (1 needs to be a different kind of string)
- 2 different plastic cups
- 2 large paper clips
- Paper towels
Here’s what you do
- Tie a 4 foot piece of string to a table leg.
- Pull it tight and pluck it.
- Repeat this with a different kind of string.
Does it make a sound? What does it sound like to you? How are the strings different?
- With the two different kinds of string, slide the string between your thumb and index finger
Does it make a sound? Is it quiet or loud? How would you describe the sound for the two strings?
- Untie the strings from the table leg.
- Carefully poke a hole in the bottom of the two different cups.
- Put the loose end of your string through the hole in the cup from the bottom and then tie the string to a paperclip inside the cup. Use the same string for each cup.
- Pull the string so that the paperclip is on the bottom of the cup.
- Hold one cup so that the string is loose and slide it between your thumb and index finger.
Is the sound similar to the sound it made without the cup?
- Next, fold a paper towel into quarters and use water to wet the towel.
- Pinch the string with the wet towel and slide the towel down the length of the string.
How is this sound different?
- Now tie the string to a table leg again and pull the cup so that the string pulls very tightly against the table leg.
- Pluck the string. If you have a friend, have them pinch the string at different points while you pluck.
- Repeat this with the other cup.
What does it sound like now? How do the different cups and different strings compare?