From the page: The disposable cup deserves a second chance
Idea 9
Musical castanets
Castanets carry a thousand years of Iberian tradition and work by impact: two hollow shells striking each other create a dry, clacking sound, amplified by the air trapped inside them. A rigid plastic cup does exactly that job — the wall vibrates and the cavity acts as a small resonating box.
What you need
- 2 rigid plastic cups (from soda or coffee, the same size)
- Strong tape or a thick rubber band
- Scissors
- Optional: a few dots of hot glue for reinforcement
How to make it
-
1
Wash and dry both cups well; any residue inside muffles the vibration and the sound loses its snap.
-
2
If the cups have a ridged rim, trim it with the scissors so it's smooth and even — the rim is the impact surface, and a clean edge clacks better.
-
3
Join the cups bottom to bottom, well aligned, using tape or a rubber band crossed around the outside. It's the meeting of the two closed cavities that creates the air chamber.
-
4
Wedge your thumb between the cups or hold the set by the middle, leaving the openings free to strike each other with a quick snap of your fingers.
-
5
Test the sound by tapping with varying force: the stiffer the plastic and the drier the strike, the louder and snappier the sound.
Finishing touches
Decorate with ribbons tied at the base, like traditional castanets, or make pairs in different sizes to create two tones — the bigger cup sounds lower, the smaller one higher.
This is one of the ideas from the full page — see all the possibilities.
This page feeds the collective knowledge 🌱 — every discovery makes the next answer better.