Movement and energy in a system

  • How do musical instruments make music?
  • Are there different types of musical instruments in different parts of the world?

This chapter leads on from the last in that it is taking movement energy further and looking at how movement energy produces sound energy in the form of the parts of the instrument that move and the vibrations which carry the sound energy.

NB : A suggestion is to do the next chapter on "Energy and Sound" before this chapter on "Movement and energy in a system" instead of after it as stated in CAPS. There are many concepts in the chapter on "Energy and sound" which can be used when learners have to make a musical instrument in this chapter. Logically and conceptually, this does make more sense as sound is introduced as a form of energy in the previous chapter on "Energy around us" and then the chapter on "Energy and Sound" investigates sound further, before sound is applied to the use in musical instruments. This, however, is your choice as a teacher and as to how you would like to progress through the chapters.

Movement and musical instruments

Look at the photo of the orchestra. There are many different instruments that all make music. All the sounds are combined together to make a wonderful noise.

An orchestra consists of many musical instruments playing together.
Let's make some music!

The joy of sound - making a body band


  1. Work in groups of 4 - 5.
  2. You can make music with your body. You can clap your hands or stamp your feet. You can make clicking sounds with your tongue or puff out your cheeks and tap them. You can beat a rhythm on your thighs.
  3. In your group, find interesting ways to use your bodies to make a short (1 minute) music piece.
  4. Be creative. Present your 'body band beat' to your class.
  5. Some of you could even dance while the others make the music!

Movement causes sound

In your body band, you made lots of different sounds. Every sound that you made involved you moving a part of your body.

Many musical instruments use movement to make sounds. Let us look at a few common musical instruments.

A man plucking the strings on a guitar

When a guitar string is plucked, the string vibrates and causes a sound wave to occur. The sound is amplified (made louder) by the air vibrating in the hollow inside of the guitar as well. We can then easily hear the sounds produced by the guitar.

A group of drum players

A drum has a thin membrane or skin that is stretched tightly over the opening of something hollow. As the drummer beats this membrane, the membrane vibrates and makes the sound we hear.

A trumpet player in a marching band

The trumpet player blows through closed lips into the trumpet. This makes a buzzing sound which causes the air inside the trumpet to vibrate. The vibrating air causes sound which we can hear.

Many musical instruments work because movement causes vibrations which cause sound.

Indigenous musical instruments in South Africa

Music and musical instruments are very important in many cultures and societies. Different cultures have different musical instruments which are part of their traditions. The instruments which were developed by a group of people and are used in a particular area, are called indigenous instruments. Indigenous instruments are unique to a particular society or culture.

Although the instruments are different, they all work because movement causes vibrations which cause sound.

Africa has a rich musical culture and many unique musical instruments. Some examples are shown below.

On the front cover for Energy and change, one of the Thunderbolt Kids is playing an instrument on the beach! Who is it and what instrument is it?

Farrah is playing a marimba.

Let's look at examples of Western and African instruments. We will look at musical instruments in which you blow, and at musical instruments where you pluck the strings. There are lots of similarities in the instruments of these two cultures.

Musical instruments from two different cultures

The idea of this activity is not to juxtapose the differences in the instruments between African and Western cultures. Rather, it aims to highlight the similarities between both cultures, such as similar instruments which are played in similar ways, but made from different materials. A suggestion here is to start this activity with a class discussion on what a culture is, how different learners perceive culture and what it means to them and to highlight the many cultures that we have in South Africa. Encourage learners to start expressing their opinions and ideas by asking direct questions. Then go on to do the activity below.


  1. Study the examples of musical instruments shown in the following table.
  2. Pay special attention to how each one is played and the material they are made from.
  3. Answer the questions that follow.

Western Culture

African Culture


Kwela Flute

French Horn

Kudu Horn




Traditional Musical Bow instrument


Compare the instruments by filling in the table below:


How it is played?

What is it made from?


Kwela Flute

French horn

Kudu horn




Traditional musical bow


How it is played?

What is it made from?



Silver-plated metal

Kwela Flute



French horn



Kudu horn


Horn of a kudu, beads to decorate



Wood and nylon strings



Wood, cloth and string



Wood and string made from steel

Traditional musical bow


Sticks, calabash, string made from hide

Remember when we spoke about input and output energy? What do you think is the input energy and output energy for most musical instruments?

The input is movement and the output is sound.

Let's now make our own musical instruments!

Design and make your own musical instrument

Learners need to research, design, make and evaluate a musical instrument. Examples they could consider include: guitar, pan pipes, whistles, flutes. The scene is set below with the Thunderbolt Kids needing to make musical instruments for a local festival. The emphasis is on indigenous instruments, although not limited to this. The learners should be encouraged to identify one of the characters to help to design and make an instrument following the Design Process.

The educational value in Technology lies in the investigating, thinking and designing that children must do. Technology aims to make children capable; capability means the children's ability to turn thinking into doing and completing. When they learn new scientific knowledge, the learning has a purpose: they must use that knowledge in producing good designs. When they have made a product, they should be able to explain to you all the reasons why they designed it like that (even if they could not make it in the way they wanted to).

Some very important learning happens during a Technology project, and you need to guide the learners through all the stages. If you trained as a technology teacher, you will recognise the NCS pattern of technology projects -- do you remember IDMEC? You can remind the learners of this:

I stands for Investigating the problem which some people have, investigating existing products, and investigating concepts and skills that you will need to solve the problem.

D stands for Designing -- that means using what you learnt from investigations to think of good ways to solve the problem.

M stands for Making -- when you make your model, you use materials and tools, you make your model look good, and you show the teacher what you learnt in your investigating." (Notice that most children design with their hands, not only with pencil and paper. As they work with materials they get more ideas, and their design improves. So we should expect them to go back and forth between Designing and Making. It's really all the same stage of a project.)

E stands for Evaluating -- after you have made your model to solve the problem, you have to ask, does it work? Is this what the people wanted? Could we make a better one?

C stands for Communicating -- you must show other people how you decided on your solution to the problem. You need to write and draw your ideas." (The learners should be drawing and writing all through the project. Don't leave the writing to the end, because they find it boring at that stage. When they are getting new ideas they often enjoy writing because they are writing about their own ideas; this is a great strength of technology in school. A technology project gives the children reasons for reading and reasons for writing. And so - this is very important - we can address the literacy problem through the subject of science and technology.)

The Thunderbolt Kids want to participate in the local Arts Festival after the holidays. They want to make a band of four and participate in the section for indigenous bands. Any instruments used must be indigenous instruments which are handmade.

The Thunderbolt Kids want a variety of different instruments. Sophie can play the flute so she would like an instrument which she can play by blowing, such as a whistle or pan pipes. Tom likes to play his electric guitar, but he can't use this as the instruments need to be traditional and handmade, so Tom needs an instrument which he can play by plucking strings. JoJo loves playing the drums and Farrah likes to dance with a shaker!

Check out their photo below which they had taken for their poster to advertise for the festival!

The problem is, none of the Thunderbolt Kids have an instrument to play. So you need to help one of them to design and make a musical instrument.


You need to design and make an instrument for one of the Thunderbolt Kids. Write a design brief below where you identify which Thunderbolt Kid you are going to help and which type of instrument you are going to make.


The next step in the Design Process is to investigate and do some research about the instrument that you are going to make. You can use books and the internet to do your research. Perhaps you know someone who plays this instrument?

We already looked at some instruments and what they are made from and how they are played.

Answer these questions when doing research about your instrument:

  1. How do you play the instrument?

  2. What is it normally made from?

  3. Is this instrument part of any culture and their traditional ceremonies?

  4. What other interesting facts did you find out about this instrument?


Now that you know a bit more about the instrument, you need to design how you are going to make your own.

Your instrument has the following specifications:

  • It must make a sound by blowing on it or by plucking strings.
  • You must be able to play at least two different sounds.

Your instrument has the following constraints:

  • You must make it in class.

Answer these questions:

  1. What shape and size will your instrument be?

  2. What materials will you need to make it?

  3. What tools will you need to make it?

Now you need to draw some designs for your instrument. Use scrap pieces of paper to do your first designs. Once you are happy with your design, use the space provided to draw your design. Label your drawing showing what materials you are going to use for the different parts.

When you are making your instrument you might get better ideas to improve the sound. So come back afterwards and draw on the bottom half of the page; show what you really decided to make.


Now make your instrument in class! After you have all finished making your instruments, take turns to play them for each other. Perhaps you can even form your own bands!

Once learners have finished making their instruments in class, go around and evaluate whether each learner's instrument can be played. You can do this as a whole class where each learner has a chance to present their instrument, explain what it is, and then attempt to play two different sound. If time permits, you can break the class up into groups and they can form a band where they have to put together a song and then present it to the class.


Answer the following questions on your musical instrument after you have finished making it and testing to see if it can be played.

  1. Does your musical instrument look like your initial design?

  2. How do you play your instrument?

  3. Can you play two different sounds (notes) on your instrument? If not, why can't you?

  4. How would you improve your design so that your instrument makes a better sound or is easier to play?


Now, do not forget that we were trying to help the Thunderbolt Kids design and make musical instruments for their local arts festival!

Write a paragraph, where you tell the Thunderbolt Kid whom you decided to help, about the musical instrument that you made. Tell them what worked and what did not work, so that they can also learn from what you did and make a great instrument to play in their band!

Wow, thank you for helping us out with our band! We could not have done it without you!
  • Many musical instruments use movement input energy to work.
  • Many musical instruments have parts that can move or vibrate.
  • Sound is the main output energy of musical instruments.

What do most musical instruments have in common that allow them to make music?

A moving part that causes vibrations

Sounds are caused by vibrations. What is a vibration?

A vibration is a very quick movement (to-and-fro) of an object or its parts in the same place.

How do you make a sound on a guitar? And how do you think the shape of the guitar helps to make the sound louder?

You make sound by plucking the strings. The sound is amplified (made louder) by the air vibrating in the hollow inside of the guitar.

What does the word 'indigenous' mean?

originating and characteristic of a particular place or people

What is your favourite musical instrument? Explain how it looks, how you would play it, and why you like it so much.

Learner dependent answer