1. Sound. Qualities of sound

Music is made by sound. But, what is sound made of? What is it?

When we hit an object, when we pluck a tight string, when we blow through a tube, when we speak and sing; we make sounds.

In order to turn sound into music, there must be an expressive intention.

The first step will be to work on the different qualities of sound, which have their own graphic representations on the staff: conventional notation symbols, as well as the so called alternative graphic notation.

	We are going to learn to...	Basic skills
Performance and creation	Recognize sound as a physical phenomenon. Experiment with sound, noise and silence as means of musical and personal expression. Use our voice, our body, objects and musical instruments in order to investigate the different qualities of sound, and also to enhance its expressive possibilities. Identify the qualities of sound and their representation with alternative graphic notation. Creatively investigate the different acoustic and musical possibilities of objects. Show interest in the composing and improvisation activities, and respect their classmates’ creations. Actively participate in the different musical activities by playing different roles, providing ideas and contributing to the perfection of the common task.	CCL CMCT CPAA CSC SIE
Listening	Recognize sound and silence as constituent parts of music. Appreciate silence as a requirement in order to take part in the listening. Identify the work of the different qualities of sound in the listening. Describe a composition’s parameters by using alternative graphic notation. Identify everyday situations in which sound is indiscriminately used, analyze its causes and provide possible solutions.	CMCT CPAA CSC SIE
Musical and cultural contexts	Become aware of the problems created by noise pollution and its consequences. Show interest in discovering different types of music and expanding their own musical preferences while adopting an open and respectful attitude. Value the need of handling different basic musical concepts in order to be able to talk about and judge music. Clearly and accurately communicate their knowledge and musical opinions, verbally as well as in writing. Read different types of scores as backup for the musical activities of the class.	CCL CMCT CPAA CEC
Music and technology	Easily find their own way with the necessary technological resources for recording and playing music. Use the available computer resources in a practical way in order to learn and investigate music. Easily handle the right sources and procedures in order to carry out the proposed tasks. Become aware of the contribution of music to the human experience, and show a more critical attitude towards the indiscriminate consumption of music.	CCL CMCT CD

1.1. How it is produced

Sound is produced when an object vibrates and that movement travels through sound waves until it reaches our ears.

↑ The vibration of an object travels through sound waves.

1.2. How it propagates

Sound propagates at high speeds. The waves travel through the air at 340 meters per second, and they are transmitted the same way waves spread on water when we throw a stone.

Usually, sound travels through air, but it can also travel through other mediums like water or solid objects. In fact, sound travels faster through water (1.435 m/s) and even faster through materials like wood (3.900 m/s) or iron (5.000 m/s).

1.3. How we hear

Sounds are picked up by a very thin membrane in our ear, the eardrum, which connects the outer and middle ear. When sound waves hit the eardrum, the information produced by its vibration is transmitted to the brain.

Reverb and echo

Reverb is produced when sound waves find obstacles on their way. They are reflected or bounced back in the opposite direction of the sound source.

Echo is a kind of reverb that creates the repetition of sound. When the time-lapse between the emitted and the reflected sounds is wide enough, we perceive them both separately.

The echo and the reverb of sound are very useful phenomena of nature. For example, they allow bats find their way while flying; and make it possible for sailors to measure the depth of the sea or let them know where a school of fish is.

The eardrum’s vibrations are turned into nerve impulses. They transmit the information to the brain.

ACTIVITIES

If you put your ear to the table and hit the wood gently with your fingers, you’ll notice how well sounds propagate through solid objects. Try to make it louder and softer putting your ear away from the table. Write your conclusions.

Investigate your surroundings and give examples which prove the different speeds of sound depending on the physical mediums.

2.1. Silence in music: rest*

Silence is the absence of sound, the lack of hearing sensation.

Actually, there isn’t such thing as absolute silence. Even if we could isolate ourselves completely from outer sounds, we would still hear our own body’s inner sounds.

When we talk about silence in music, we understand it, therefore, as something relative; as «the blank space of music».

Functions of rests in music:

Silence is an element as important as sound in music.

It is the indispensible previous condition to enjoy music: we begin with silence when hearing and performing a composition.

It serves as a break, to catch one’s breath.

It is a resource of great expressive energy: a rest at the right time can have more meaning than the best of sounds.

It makes it possible to organize ideas and give structure to the whole composition.

Rest

Is the term used in musical notation to indicate a period of silence on the score.

Mosquitoes make their wings vibrate around 510 times per second. That is why their sound is more noticeable.

ACTIVITIES

J. S. Bach. Toccata and fugue in D minor

What instrument performs it?

This music sure sounds familiar to you, where did you hear it?

This fragment consists of several short musical phrases, how many?

Can you point out the phrases on the staff?

Can you recognise rest notes on the score?

What correspondance can you find between rest notes in this piece and punctuation marks in written languages?

What do these rests make you feel?

If you were a movie director, in what scene would you play this background music? Write a short text describing the situation.

Sound has four qualities or parameters which allow us to identify it: pitch, duration, intensity and timbre.

If we try to describe a sound with words, we have to point out:

If the sound is high or low, that is, the pitch.
If the sound is long or short; we point out the duration.
If the sound is loud or soft, that is, the intensity.
If the sound comes from a voice or an instrument; we point out the timbre.

As we saw before, sound is produced by vibrating bodies. Therefore, the different qualities of sound are due to the different shapes and characteristics that those vibrations may have.

Writing music

Musical notation consists of representing as precisely as possible all four qualities of sound: pitch, duration, intensity and timbre.

The symbols we use today are the result of a long evolution throughout history, from the need of preserving and being able to perform music.

The color of sound

When we hear a sound, it is never pure. It is a mixture of sounds with different frequency and vibration amplitude.

Just as the combination of different colours creates another colour, the combination of harmonic sounds creates different timbres.

The pitch of sound depends on the wave frequency: the vibration speed. It is measured in units called hertzes (Hz) which show the number of vibrations per second.
The duration of sound depends on the wave persistence: how long the wave lasts until fading out.
The intensity of sound depends on the wave amplitude: the distance between the points of highest vibration and repose of the object. It is measured in units called decibels (dB).
The timbre depends on the mixture of root and harmonic sounds, which are different in each voice or instrument.

Look at this chart in which we describe the qualities of sound by indicating the physical phenomena that produce them.

We use musical notation to represent the different working possibilities of sound; creating it, as well as performing and preserving it.

Currently, along with conventional notation (which we are about to see in the following units), some alternative symbols are used too. They are capable of meeting the needs of contemporary music and its new sounds, in a more expressive and open way.

4.1. Pitch symbols

If we distinguish between high or low pitch, the simplest way of representing these opposites would be:

Braille musical notation

Louis Braille (1809-1852), creator of the reading system for blind people, also invented a musical notation based on raised dots.

It consists of grouping six dots in two vertical columns of three, raising certain combinations so that the reader can feel them.

For the names of the notes, he combines the four upper dots:

For the duration, he combines the two lower dots:

Accidentals, time signatures and other elements are represented using different combinations with the whole group of six dots.

4.2. Duration symbols

If we distinguish between long and short duration of sound, we can represent it with horizontal lines or rectangles for long sounds, and dots or squares for short sounds.

4.3. Intensity symbols

If we distinguish between loud or soft intensity sounds, we can represent them by changing the size of the symbol or the color intensity:

4.4. Timbre symbols

In conventional notation, timbre does not have a specific symbol, so it is represented by just writing the corresponding name of the voice or instrument.

However, when using alternative symbols in graphic notation, it is very common to represent the various timbres referring to the material of the instrument or the way the sound is made:

In this word search puzzle find (vertically and horizontally) all the concepts we have seen regarding the qualities of sound.

Match the waves with their corresponding sounds:

Low
High
Loud
Short
Long
Soft

Draw in your notebook a picture of:

a low and loud sound
a long and soft sound
a high and long sound
a soft and short sound
a low and soft sound
a loud and high sound

a long and low sound
a low and short sound
a low, soft and long sound
a high, long and soft sound
a high, loud and short sound
a low, short and loud sound

Complete the following chart summarizing the qualities of sound:

QUALITIES	DISTINCTION	PRODUCED BY

Find out the mistakes of the following statements and write them correctly:

Sound is produced when the vibration of waves is transmitted as a body up to our ears.
Sound propagates through air at 340 kilometers per minute.
The ear picks up sounds with the vocal chords, which connect the inner and middle ear.
The qualities of sound are: pitch, duration, intensity and loudness.
The pitch of sound depends on the wave persistence, which is the vibration speed.
The intensity of sound depends on the wave frequency.
The pitch allows us to distinguish between low and soft sounds.
The timbre depends on the mixture of just one sound.
The duration allows us to distinguish between low and short sounds.
Conventional musical notation tries to represent the size of sound.
The duration of sound depends on the vibration frequency.
The intensity of sound allows us to distinguish between loud and high sounds.
The timbre allows us to distinguish between loud and soft sounds.
Echo is a kind of reverb which makes sound louder.
Sound propagates at a higher speed through air than through iron.

Take a look at the indications seen in the cards below:

Your teacher will individually and secretly give you one of these cards to perform it.
In order, one at a time, using your voice or an instrument of the class, you will perform the sound or the group of sounds your card indicates. Think twice if you decide to use an instrument, not all instruments have the same acoustic possibilities. You have to choose the best one.
Your classmates will write it down to try to guess the card you perform.

Pay attention to the instructions of the chart bellow and perform this piece with the whole class.

Listen to these four musical pieces we present you:

/useruploads/ctx/a/39583569/r/s/9552299/I_Pista02_cd1_632493.mp3?idcurso=769769 · Holst. The Planets. Jupiter.

/useruploads/ctx/a/39583569/r/s/9552299/I_Pista03_cd1.mp3?idcurso=769769 · Brahms. Symphony No. 3. Poco Allegretto.

/useruploads/ctx/a/39583569/r/s/9552299/I_Pista04_cd1.mp3?idcurso=769769 · Beethoven. Symphony No. 7. Allegretto.

/useruploads/ctx/a/39583569/r/s/9552299/I_Pista05_cd1.mp3?idcurso=769769 · Richard Strauss. Thus spoke zarathustra.

Which do you think is the predominant quality of sound in seach one of these fragments? Match each track with its most highlighted quality.

Holst. The Planets. Jupiter.
Brahms. Symphony No. 3. Poco Allegretto.
Beethoven. Symphony No.7. Allegretto.
Richard Strauss. Thus spoke Zarathustra.

duration
pitch
intensity
timbre

Which of the following pictures would you choose to represent each track?

a)

b)

c)

d)

Choose some of the adjectives below to describe what the tracks make you feel or the mood they put you in.

shiny
energetic
optimistic

monotonous
delicate
sad

surprising
bold
disturbing

simple
clear
calm

Look at the following chart in which the different speeds of sound are expressed in meters per second. Fill the right column calculating the speed of sound in kilometers per hour.

physical medium	speed m/s	speed km/h
Oxygen	317
Air	340
Lead	1.190
Hydrogen	1.286
Water	1.450
Copper	3.810
Wood	3.900
Aluminium	5.100
Iron	5.190
Granite	6.000

Write your own musical composition using alternative graphic notation:

– First, think about the environment you want to represent. You can compose a soundtrack that reflects, for example, the sounds of the city, the country, the sea, an action scene, etc.

– Choose the timbre with which you are going to represent all the elements of your soundtrack. You can choose among the instruments of your class, voice or instruments you can make with various objects. Create a symbol for each instrument which identifies it clearly.

– Draw two axes (vertical and horizontal) in order to write your score. On the vertical line you will indicate the intervention of the different instruments or voices. On the horizontal line, you will indicate the durations on a scale expressed in seconds.

– Ask your classmates for help to be able to perform your score and dare to conduct your composition.

1

Sound is a hearing perception produced by the vibration of an elastic body, and is transmitted through air, liquid or solids up to our ears.

2

Silence is as important as sound in music. It is indispensible to enjoy music. It gives structure to the musical discourse and can be used as a resource of great expressive energy.

3

Sound has four qualities or parameters which allow us to identify it: pitch, duration, intensity and timbre.

4

The pitch allows us to distinguish between low and high sounds. It depends on the wave frequency.

5

The duration allows us to distinguish between long and short sounds. It depends on the wave persistence.

6

The intensity allows us to distinguish between loud and soft sounds. It depends on the wave amplitude.

7

The timbre allows us to distinguish between voices and instruments. It depends on the mixture of root sounds with its harmonics.

8

Musical notation consists of graphically representing all four qualities of sound.

Alternative graphic notation is a nonconventional notation which allows us to write music in a more expressive and open way.

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1 Sound

1.1. How it is produced

1.2. How it propagates

1.3. How we hear

2 Silence

2.1. Silence in music: rest*

3 Qualities of sound

4 Alternative graphic notation

4.1. Pitch symbols

4.2. Duration symbols

4.3. Intensity symbols

4.4. Timbre symbols

Self-assessment

Performance

Creation

Listening

Challenge

To sum up

My progress