Unit 4
Grammar
55
CD2
15
1
Listen and repeat.
[photo 073l]
Project
6
Find out about an
instrument. Draw it and
describe how it makes
sounds. How can you
change the pitch?
2
Watch the video.
thick string
thin string
make tighter
vibrate
4
Answer the questions.
What word describes how high or low
sounds are?
2
What do we hear when something
vibrates slowly?
3
Which makes a higher sound, a long
string or a short string?
4
Which makes a lower sound, a thick
string or a thin string?
5
What sounds do you hear every day?
Do they have a high or a low pitch?
high and low
sounds
?
➞
Workbook page 44
3
2
When we play a guitar or another string
instrument, we make the strings vibrate. When
a string vibrates quickly, it makes a high sound.
When it vibrates slowly, it makes a low sound.
The pitch is how high or low the sound is. How
can we change the pitch? There are three ways.
•
We can make the string tighter. Tight strings
vibrate faster, so they make a higher pitch.
•
We can make the string shorter because
shorter strings vibrate faster, too.
•
We can use thick and thin strings. Thick
strings vibrate slowly and make a low sound.
Thin strings vibrate quickly and make a
high sound.
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