Transcript Garage Band WS 2 - Wayzata Public Schools

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
Acoustics WS
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.
Acoustics WS
4. A single vibration (one complete sound
wave) is called a CYCLE.
5. On the line below, diagram a complete wave
cycle.
Acoustics WS
TYPES OF SOUND WAVES
1) Sine Wave
2) Triangle
3) Pulse/Square
4) Sawtooth
Acoustics WS
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
Acoustics WS
Frequency
7. 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.)
Acoustics WS
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 - C
Lowest in Pitch - B
Acoustics WS
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.)
Acoustics WS
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.
Acoustics WS
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)
Acoustics WS
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.
Acoustics WS
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.
Acoustics WS
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.
Acoustics WS
20. In the space on your paper, show a sample of
the fundamental and overtone series:
Minor 3rd
Overtones
Major 3rd
Perfect 5th
Perfect 4th
1 octave
Perfect 5th
1 octave
Fundamental
Acoustics WS
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.
Acoustics WS
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.
Acoustics WS
23. A synthesizer uses an ENVELOPE
GENERATOR to set the parts of a note’s
duration. It usually has three parts:
•Attack
(Time)
•Sustain
(Key Held Down)
•Decay/Release
(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.
Acoustics WS
Questions . . .