Sound Science: Craft Stick Harmonica


Materials for this Take and Make will be available at area PPLD libraries, beginning Feb. 10, 2023.

Supplies and Directions:

For additional pictures of this project, click on the pdf file link below.)

Jumbo craft sticks (2)

A wide rubberband

Two smaller rubber bands

A straw

You provide the scissors.

1. Cut two pieces of straw that are 1 – 1 .5 inches long.

2. Stretch the thick rubber band around one of the craft sticks.  Place one of the straws under the rubber band.
3. Put the other craft stick on top and attach them with one of the small rubberband on the same end as the straw.

4. Stick the other piece of straw at the other end of the harmonica, but this time place it on top of the wide rubber band.  Secure the end with the second small rubber band.

5. To play the harmonica, all you have to do is blow.  Our younger kids were wanting to hum into it at first, but then they got the hang of it.

It makes a really cool noise!  When you blow, the wide rubber band vibrates and makes a sound.
To change the pitch, slide the straws closer together or farther apart.  When you slide them closer together, the section of rubber band that is vibrating is shorter, so it makes a higher sound. Slide the straws all the way to the edges to get the lowest possible sound (which is still pretty high, but lower).

Make it an experiment!

Does the thickness or the tension of the wide rubber band affect the pitch?  Try different ones.

Can you change the pitch by blowing harder or softer?  Does the shape of your mouth affect the pitch? (Yes, it does! One of my boys figured out how to play a song by blowing different ways.)