music 101-150

Question 1

In a sound wave, what is the difference between compression and rarefaction?

Answer 1

A sound wave moving through the air causes pressure changes. Compression refers to the space where air pressure is increased, while rarefaction is the area where air pressure is decreased. One cycle of compression and rarefaction creates a complete sound wave.

Question 2

What is a “period” as it relates to the physics of sound?

Answer 2

A period is the length of time that a sound wave takes to complete one cycle of compression and rarefaction creates a complete sound wave.

Question 3

What physical property of a sound wave determines its pitch?

Answer 3

The frequency of the sound determines its pitch.

Question 4

What physical property of sound does frequency measure?

Answer 4

Frequency measures the rate of the vibrations of a sound in hertz.

Question 5

What is the unit of measurement for frequency, and for whom is it named?

Answer 5

The unit is named after Heinrich Hertz, a German physicist; hertz measures the frequency of a sound wave in cycles per second. One hertz is one cycle per second.

Question 6

In what way does a change in the frequency of a sound after its ptch?

Answer 6

Higher frequencies correspond to higher pitches, and lower frequencies correspond to lower pitches.

Question 7

Who is believed to have first discovered that musical pitches are related to each other by specific ratios?

Answer 7

Pythagoras

Question 8

Notes that are separated by an octave are how many half steps apart?

Answer 8

Two notes an octave apart are separated by 12 half steps.

Question 9

What is the ratio between the frequencies of two notes that are separated by one octave?

Answer 9

2:01

Question 10

If a given note has a frequency of 440 Hz, what is the frequency of a note that is one octave higher?

Answer 10

880 Hz (440 x 2)

Question 11

In modern Western music, what is the standard frequency used in most orchestras of the tuning note A4?

Answer 11

440 Hz

Question 12

How many pitches are contained in one octave of a chromatic scale?

Answer 12

One octave of the chromatic scale consists of 12 pitches spaced fairly evenly throughout the octave. If these pitches have been obtained by precisely dividing the frequencies between the two octave notes, then the scale has been tuned with equal temperament.

Question 13

What is a “sound envelope”?

Answer 13

“Sound envelope” is the term used to describe the lifespan of a sound.

Question 14

What are the three parts of the sound envelope?

Answer 14

The sound envelope consists of the attack, sustain, and decay of a sound.

Question 15

What creates the attack of a note?

Answer 15

The attack is caused by the initial resistance of the instrument to the force causing the sound vibrations, such as the movement of a bow on a string.

Question 16

What is happening to the wave during the decay of a sound?

Answer 16

The decay of a sound is created by the decrease in force and amplitude of the vibrations of the wave.

Question 17

What is amplitude?

Answer 17

Amplitude is the distance that a wave moves from its equilibrium position while vibrating.

Question 18

What is intensity?

Answer 18

Intensity is a measure of the power, or energy per second, of a sound wave as it vibrates.

Question 19

How are amplitude and intensity similar?

Answer 19

Amplitude and intensity both affect the volume of a sound wave as it is perceived by the ear.

Question 20

What is the relationship between amplitude and frequency?

Answer 20

Ideally, there is none. A strict change in the frequency of a pitch will not change its amplitude, and vice versa.

Question 21

Describe the amplitude and frequency of a note that is low-pitched and loud.

Answer 21

The low pitch is a result of a low frequency, and the loudness a result of a high amplitude.

Question 22

What unit is used to measure amplitude?

Answer 22

decibel (dB)

Question 23

From what scientist does the decibel take its name?

Answer 23

A decibel is one-tenth of a bel, which is named after Aexander Graham Bel..

Question 24

What does a measurement in decibels indicate?

Answer 24

A measurement in decibels gives the ratio between the intensities of two different sounds

Question 25

What is the decibel measurement for the human threshold of hearing?

Answer 25

0 dB

Question 26

Why is the measurement of 120 dB significant?

Answer 26

An amplitude of 120 dB is the human threshold of pain.

Question 27

What does the term “dynamics” refer to?

Answer 27

Dynamics describe the different volumes in a piece of music such as forte or pianissimo.

Question 28

What language is used for indicating dynamics in music?

Answer 28

Italian

Question 29

Put the following terms in order according to the level of volume that they indicate, from softest to loudest: forte, mezzo piano, pianissimo, fortissimo, piano, mezzo forte

Answer 29

pianissimo, piano, mezzo piano, mezzo forte, forte, fortissimo

Question 30

What is the difference between a crescendo and decrescendo?

Answer 30

A crescendo indicates a gradual increase in the volume of music; a decrescendo indicates a gradual decrease in the volume of music.

Question 31

What is timbre?

Answer 31

Timbre refers to the qualities of a sound that distinguish it from another sound of the same pitch and volume. Timbre is also known as “tone color.”

Question 32

What are harmonics?

Answer 32

Harmonics, or overtones, are the pitches above the fundamental that occur naturally when a sound is produced.

Question 33

what is the interval between a fundamental pitch and its first overtone?

Answer 33

The first harmonic, or overtone, is exactly one octave higher than its fundamental pitch.

Question 34

What type of sound does a sine wave represent?

Answer 34

A sine wave represents the sound wave of a note with no overtones.

Question 35

What sort of wave is used to represent a pitch that is heard with only odd overtones?

Answer 35

A square wave.

Question 36

What sort of overtones are present in a sawtooth wave?

Answer 36

A sawtooth waveform is used to indicate a pitch that is heard with all of its overtones.

Question 37

Name three factors that affect the sound spectrum of an instrument

Answer 37

The sound spectrum is affected by the frequency of the fundamental; the number, distribution, and intensity of the overtones; and the interactions between the harmonics themselves.

Question 38

What cause interference?

Answer 38

The overlap of multiple simultaneous sound waves

Question 39

What is constructive interference?

Answer 39

constructive interference occurs when simultaneous sound waves “in phase”;: they match up trough to trough and crest to crest, resulting in an amplitude that is the sum of all of the individual amplitudes.

Question 40

What is the product of constructive interference?

Answer 40

Constructive interference results in a sound wave with an amplitude equal to the sum of the amplitudes of its component waves.

Question 41

What causes destructive interference?

Answer 41

Destructive interference occurs when two interacting waves are “out of phase”: they are not perfectly aligned.

Question 42

What is the result of destructive interference?

Answer 42

Destructive interference fully or at least partially cancels out the amplitudes of its component waves.

Question 43

What causes beats?

Answer 43

Beats are caused by the interference between sound waves that are cycling between being out of phase, (which decreases the amplitude) and in phase (which increases the amplitude).

Question 44

What determines the number of beats per second created by two interfering sound waves?

Answer 44

the number of beats per second created by two interfering sound waves is equal to the difference in frequency between the two waves (f1 - f2 = bps).

Question 45

diatonic

Answer 45

within the key

Question 46

Which scale degrees correspond to major triads in a major key

Answer 46

1,4,5

Question 47

which scale degrees correspond to minor triads in a major key

Answer 47

2,3,6

Question 48

why does the dominant triad resolve to the tonic

Answer 48

it contains both the fifth scale degree and the leading tone

Question 49

predominant harmonies

Answer 49

harmonies that pull to the dominant chord

Question 50

on which scale degrees are the most common predominant harmonies based

Answer 50

2,4

Question 51

what is the most common chord progression

Answer 51

predominant, dominant, tonic