Unit: Experimenting with sound

Part A: About sounds

Lesson outcomes

Distribute Student handout 2: What is sound? Work through the handout as a whole class, providing support for student responses through discussion and musical examples.

Questions 1–3: What is sound?

Ask the students what they think sound is. Distinguish between sound as anything we can hear and noise as unwanted sound. Ask individual students for examples of sounds they consider to be noise and sounds they like that others may consider to be noise. Note that noise is not always loud. It may be an irritating or annoying sound such as someone rustling a chip packet during a suspenseful part of a movie.

Remind students that sound is the common ingredient of all music. Ask students to record responses to questions 1–3 on their handout.

Question 4: Silence

Ask students: what is the opposite of sound? (Answer: silence)
Record a response to question 4 on the handout.

Question 5: Is there such a thing as complete silence?

Find out by sitting completely still for two minutes. In this time, if any sound is heard, students write it down next to question 5 on the handout.

Create a class list of the sounds that were heard. Introduce the term environmental sounds to describe the sounds around us. Explain that environmental sounds are divided into three categories according to the way they are produced:

natural sounds such as birds, wind or animal sounds
human sounds produced by the human body by itself, such as clapping or sneezing
mechanical sounds produced by manufactured objects such as car engines, door hinges creaking or phones.

Label the sounds heard during the silence exercise as either N (natural), H (human) or M (mechanical).

Questions 6 and 7: Vibrations

Demonstrate the concept of vibration by asking students to observe and describe what they see when the largest string on a double bass or cello is plucked. Explain that when the string vibrates it makes the air around it vibrate as well, creating sound waves. These travel through the air to our ears and make our eardrums vibrate. Our brain translates these vibrations into sound.

Ask students to record a response to questions 6 and 7 on the handout.

Questions 8 and 9: Why are some sounds high and some sounds low?

Pluck the largest string on a double bass and an unamplified electric bass guitar.
Ask students why we hear the double bass string clearly, but not the bass guitar.
Students should observe that the double bass is hollow, therefore allowing the vibrations to move through the inside and bounce off the wood, amplifying the original sound, whereas the bass guitar body is solid and doesn’t allow any reverberation or natural amplification. Allow students to feel the vibrations by touching the back of the double bass as they pluck it.

Explain that the bass guitar is the electronic equivalent of the double bass. It has the same range of pitches and strings tuned to the same notes.

Pluck the thickest, then the thinnest string. Ask students to describe each sound.

Explain that the thicker or longer the string, the slower the vibrations; the slower the vibrations the lower the sound.

Compare the sound of the recorder with the double bass sound. Observe that the smaller the instrument, the higher the sound.

Ask students to record a response to questions 8 and 9 on the handout.

Questions 10 and 11: Introducing the musical concepts and the properties of sound

Distribute a percussion instrument to each student. Ensure students know the names of each instrument as they are distributed and how each one is played. Explain that the instruments will be used to explore some important features of sound.

Ask each student around the class to take turns and play ONE sound on their instrument. The next person is not to play their sound until they can no longer hear the sound of the previous instrument.

Ask students to describe what they noticed and to observe that some sounds were much longer than others. Introduce the term duration to describe the length of sound.

Ask students to determine which instruments vibrated the longest: metal, string or skin? Metal instruments vibrate for the longest time, wooden instruments for the shortest time, and skin instruments for a time span between these two.

Ask a student with finger cymbals and one with large cymbals to play a short rhythm. What was the difference? (Finger cymbals make a high sound and the large cymbals make a lower one.) Introduce the term pitch to describe the highness or lowness of sound.

Ask students to hit, shake or scrape their instrument as hard as they can, then as gently as they can. Discuss the difference, and introduce the term dynamics to describe the loudness and softness of sound.

Ask students to close their eyes. Choose a student (by tapping them on the shoulder) to play one sound on their instrument. Ask students to identify which instrument was being played, and of what material it is made.

How did you identify the instrument? Each instrument has its own individual sound quality, determined by what it’s made of and how it’s made to vibrate. Introduce the term tone colour to describe the quality of sound.

Explain that some instruments can produce a number of different tone colours. While students close their eyes, play some instruments in unusual ways, for example draw a violin bow down the edge of a cymbal, pluck or gently rub the metal snare on the bottom of the snare drum. Ask students to identify the instrument and how it was being played.

Ask students to record a response to questions 10 and 11 on the handout.

Resources

Student handout 2: What is sound?
A large string instrument, preferably a double bass or a bass guitar.
A selection of non-melodic percussion instruments, one per student. Ideally a mixture of wood, metal and skin instruments which have a wide pitch range.

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