ACOUSTICS AND THE ELEMENTS OF MUSIC

Is your name and today’s date at the top of the worksheet now?

Goals for Today’s Talk-

•Acoustics

•Sound Waves

•Four Characteristics (elements) of Sound

•Relate Characteristics back to Garage Band

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1. Acoustics is the study of the BEHAVIOR OF SOUND WAVES.

2. Every sound we hear is produced by VIBRATIONS.

3. Air disturbances move OUTWARD FROM A VIBRATING BODY IN THE FORM OF SOUND WAVES.

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4. A single vibration (one complete sound wave) is called a CYCLE.

5. On the line below, diagram a complete wave cycle.

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TYPES OF SOUND WAVES

1) Sine Wave

2) Triangle

3) Pulse/Square

4) Sawtooth

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6. Name the four basic elements (characteristics) of all sound & give them a brief definition:

ELEMENTS: DEFINITION:

1) DURATION LENGTH OF SOUND; HOW IT STARTS & ENDS

2) AMPLITUDE VOLUME; HOW LOUD OR SOFT THE SOUND IS

3) FREQUENCY PITCH; HOW HIGH OR LOW THE SOUND IS

4) TIMBRE DIFFERENT TONE COLORS OF SOUNDS

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Frequency7. The frequency (PITCH) of a sound

is determined by the NUMBER OF CYCLES THAT OCCUR IN ONE SECOND OF TIME.

Example- (A440 tuner. Talk about cycles per second; octaves, et al.)

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8. Calculate the cycles per second. Determine the Highest and Lowest in PITCH of your given waveforms.

(How many cycles on each line?)A = 4 B = 2 C = 10.5

Which wave is:Highest in Pitch - CLowest in Pitch - B

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9. The audible range for the human hearing is FROM 20 cps to 16000 cps.

(cps is the abbreviation for CYCLES PER SECOND.)

10. Vibrations above 16000 cps are called ULTRASONIC and below 20 cps are called SUBAUDIO. (Examples of uses of these two types of wave.)

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11. The lower the cps or Hz, THE LOWER THE PITCH OF THE SOUND

12.The higher the cps or Hz, THE HIGHER THE PITCH OF THE SOUND.

(Note- Hz stands for “Hertz.” He discovered how to calculate cycles per second.)

•On Garage Band you change frequencies when you play different notes on the keyboard or use pitch bend.

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Amplitude

13.Amplitude is determined by STRENGTH OF THE FORCE THAT SETS THE SOUNDING BODY IN MOTION . (This is shown by the HEIGHT OF THE WAVE’S PEAKS.)

14. Example:(tuner; voice)

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15.Which wave is: -loudest? B -softest? A -gradually getting softer? C

•On Garage Band you change Amplitude by striking the keys harder or softer, changing the velocity, or adjusting a track’s volume.

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Timbre and Waveshapes

16. Every sound (instrument/voice, etc.) is identified by its own unique TIMBRE.

17. Different timbres (tone colors) are determined by PRESENCE OF DIFFERENT COMBINATIONS OF OVERTONES ABOVE A FUNDAMENTAL NOTE.

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18.A Fundamental note is THE BASIC NOTE THAT YOUR EAR HEARS.

19. Overtones are INDIVIDUAL NOTES PITCHED ABOVE THE FUNDAMENTAL. OUR EARS BLUR THEM TOGETHER. THEY ALLOW OUR BRAINS TO DISTINGUISH ONE INSTRUMENT OR VOICE FROM ANOTHER.

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20.In the space on your paper, show a sample of the fundamental and overtone series:

Overtones

Fundamental

1 octave

Perfect 5th

Perfect 4th1 octave

Major 3rd

Minor 3rdPerfect 5th

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Timbre and Waveshapes

•In Garage Band you pick the Timbre you want when you choose a certain sound with which to record.

•You can also adjust the Timbre by

using the Sound Generator under the Edit tab in the side Info window.

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Duration & Envelopes

21. The Duration of a note refers to HOW LONG THE NOTE IS HELD DOWN OR SUSTAINED.

22. The Envelope of a note refers to HOW THE NOTE STARTS AND ENDS.

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23. A synthesizer uses an ENVELOPE GENERATOR to set the parts of a note’s duration. It usually has three parts:

•Attack •Sustain •Decay/Release (Time) (Key Held Down) (Time)

•In Garage Band, you can adjust the Envelope of the sound using the Sound Generator under the Edit tab in the side Info window.

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Questions . . .