Make Your Own Harmonica

Activity Time: 45 minutes

Age Group: 3-5 grade

Key Concepts: Sound, Frequency, Pitch

Introduction

Harmonicas or mouth organs are quite an interesting instrument! In fact, it was one of the first instruments to be played in space. Harmonicas first made their appearance in 1100 B.C. with the Sheng, a Chinese instrument. However, a closer relative of the harmonica was invented by Dutch physician Christian Gottlieb Kratzenstein in 1780 and was the size of a piano! Over the next century, the size of the harmonica was reduced before spreading across Europe and the United States in the 1800s. Harmonicas are now so widely used that we are able to make them today. So let’s get started!

Supplies

Education Standards

STEL-26 Illustrate how, when parts of a system are missing, it may not work as planned
STEL-7N Practice successful design skills
STEL-8D Follow directions to complete a technological task

Objectives

Students will be able to build their own harmonica following the instructions given
Students will be able to interpret why moving the straws changes the tone

Materials Needed

2 large craft sticks (bigger than 6 inches long)
#64 rubberband (large rubberband)
One plastic drinking straw (not a bendy straw)
2 small rubber bands
A ruler
Scissors
A piece of paper
Pen or pencil

Layout All Materials Needed

This is part of the prep work.

Stretch the Wide Rubber Band Over the 1st Craft Stick Lengthwise

Use Scissors to Cut 4 Pieces of the Straw. Each Piece Should Be About 1 ½ Inches Long

Place One Piece of the Straw About 2 Inches From the Left of the End of the Craft Stick Underneath the Rubber Band. We Will Call This Piece Straw 1.

Place Another Piece of Straw to the Right of Straw 1 on Top of the Rubber Band. We Will Call This Straw 2.

Place a Third Piece of Straw 2 Inches Away From the Right End of the Craft Stick. Place This Straw Underneath the Rubber Band. This Will Be Straw 3

Take the Final Piece of Straw. Place It on Top of the Rubber Band to the Right of Straw 3. This Will Be Straw 4.

Tip 💡- Straws 1 and 4 should be closest to the end of the craft sick. Straws 2 and 3 should be towards the middle

Take the 2nd Craft Stick. Place on Top of the First Craft Stick.

Using one hand pinch the middle of the 2 craft sticks. Wrap one of the smaller rubber bands around one end of the craft sticks. The rubber band should be about 1 inch from the end of the craft sticks.

Repeat on the Other Side

Tip 💡- Pinching the craft sticks in the middle allows all 4 straws to be held in place while securing the rubber bands. If needed- ask for help from a friend or an adult to hold the craft sticks while you secure the rubber bands.

Tip 💡- There should be a small space between straws 2 and 3. If not, go back to step 6.

🎉Congratulations🎉You Now Have a Finished Harmonica. Move on to the Activity to Learn More About Frequency, Pitch, and Sound.

Use Your Pencil or Pen, Paper, and Ruler to Draw a Table Including 2 Columns and 6 Rows.

Label the first column “distance between middle straws” and fill in the column below with “3 in,” “2.5 in,” “2 in,” “1.5 in,” and “1 in.” Label 2nd column “Pitch of Sound” (high or low)

Slide Straws 1 and 4 As Close to the Ends of the Craft Sticks As Possible

Slide Straws 2 and 3 So That They Are Approximately 3 Inches Apart

Tip 💡- Use index finger and thumb to carefully move straws 2 and 3. Be careful to not pull them out of the two craft sticks.

Hold Your Instrument by Placing One Hand on Each Side of the Harmonica.

For best use make sure to place fingers near the ends of the craft sticks or right behind the rubber bands.

Tip 💡- Use a ruler to measure the distance between Straws 2 and 3 for accuracy

Now Let's Make Some Noise!

Blow through the opening between the 2 craft sticks like you would with a harmonica.

Tip 💡- Don’t blow through the straws or you won't get any sound (Why do you think that is? Think about the vibrations)

❓- What do you hear? Is the sound high or low? Do you feel vibrations when you blow into the harmonica? Does the sound or vibrations change when you suck in air through the harmonica?

Move Straws 2 and 3 So That They Are 2.5 Inches Apart

Blow Through Your Instrument Again.

❓- Note the sound that you hear. How does the sound compare to when the straws were 3 inches apart? Are the vibrations different?

Now Move Straws 2 and 3 So They Are 2 Inches Apart. Blow Through the Opening in Your Harmonica.

❓- How is the sound different from the first time you played? What about the second time? In what ways did the vibrations change from the first time to now?

Repeat Steps for “1.5 In,” and “1 In.”

❓- How is the sound different from the first time you played? What about the second time? 3rd? 4th? In what ways did the vibrations change from the first time to now? Did the sound get lower or higher when you moved the straws further away from each other?

Take Time to Reflect on What You Observed. Write Your Reflections Below Your Table or on the Back of Your Paper.

What Happened?

You just observed tone! Tone is another way to describe pitch, or the low or high sound when a note is played. Think about how your tone changed over the course of the activity. Was your tone high or low at the beginning? What about the end?

The sound was created through vibrations. The vibrations were created by the rubber band quickly moving back and forth when you blow through the opening. The big rubber band is an essential part of this activity. Without the rubber band, no sound would be created because there would be no vibrations.

Dig Deeper

How do you think the tone would change if you only moved one straw?
Would the tone or vibrations change if you used a different-sized rubber band?
What do you think would happen if you used different sizes of craft sticks?