Items Needed:

• A long cardboard tube that is about 1 1/2–2 inches (4–5 centimeters) in diameter (the cardboard tube from a roll of wrapping paper works well or you can tape two or three paper-towel rolls together; you can also use a narrow poster tube)
• Marker (any color)
• About forty 1-inch (2.5-cm) nails for every 12 inches (30 cm) of tube
• Masking or packing tape
• Two 3 x 5 index cards (or plastic end caps if you are using a poster tube)
• Scissors
• A few handfuls of raw rice or small dry beans, or a mix of such things

Steps

1. If you’re using paper-towel rolls, first tape them together to form a long tube.
2. Paper tubes have spiral seams. Use a marker to make dots about half an inch (1.25 cm) apart all the way down the spiral seam of your tube.
3. Now poke a nail all the way in at each dot. (Make sure the nails don’t poke through the other side of the tube.) You’ll need about forty nails for every 12 inches (30 cm) of tube (click to enlarge the diagram below).
4. Next, wrap tape around the tube to hold the nails in place (click to enlarge the diagram below).
5. Cut two circles from the index cards just a little bigger than the ends of the tube. Tape one of the circles over one end of the tube. Cover the circle with tape so the whole end of the tube is sealed shut. If you are using a poster tube with end caps, insert the plastic cap on one end of the tube and secure it with tape.
6. Put a handful of raw rice or beans into the open end of the tube. Cover the open end with your hand, and turn the tube over a few times, listening to the sound your rainstick makes. Add more rice or beans until you like what you hear. (Beans will make a harder sound; rice will make a softer sound.)
7. When you’re ready, tip the tube up, put the second index-card circle or plastic cap over the open end, and seal the tube shut with tape.
8. Once your rainstick is complete, you can shake it like a rattle, use it as a percussive instrument, or gently tip it back and forth to make soothing environmental sounds.

What’s Going On?

Each time a dry bean or grain of raw rice hits a nail it makes a tiny click. The nail carries the vibration of the clicking sound to the cardboard tube, which acts to convey the sound into the air, just like the soundboard on a piano.

The clicks happen at random as the rice falls through the tube, just as raindrops make sounds at random times as they fall onto a roof. This sound is called white noise. It is also the sound that AM radios make when they’re not tuned to a station.

https://www.exploratorium.edu/snacks/make-your-own-rainstick

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