Flashcards in music 101-150 Deck (51):
In a sound wave, what is the difference between compression and rarefaction?
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.
What is a "period" as it relates to the physics of sound?
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.
What physical property of a sound wave determines its pitch?
The frequency of the sound determines its pitch.
What physical property of sound does frequency measure?
Frequency measures the rate of the vibrations of a sound in hertz.
What is the unit of measurement for frequency, and for whom is it named?
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.
In what way does a change in the frequency of a sound after its ptch?
Higher frequencies correspond to higher pitches, and lower frequencies correspond to lower pitches.
Who is believed to have first discovered that musical pitches are related to each other by specific ratios?
Notes that are separated by an octave are how many half steps apart?
Two notes an octave apart are separated by 12 half steps.
What is the ratio between the frequencies of two notes that are separated by one octave?
If a given note has a frequency of 440 Hz, what is the frequency of a note that is one octave higher?
880 Hz (440 x 2)
In modern Western music, what is the standard frequency used in most orchestras of the tuning note A4?
How many pitches are contained in one octave of a chromatic scale?
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.
What is a "sound envelope"?
"Sound envelope" is the term used to describe the lifespan of a sound.
What are the three parts of the sound envelope?
The sound envelope consists of the attack, sustain, and decay of a sound.
What creates the attack of a note?
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.
What is happening to the wave during the decay of a sound?
The decay of a sound is created by the decrease in force and amplitude of the vibrations of the wave.
What is amplitude?
Amplitude is the distance that a wave moves from its equilibrium position while vibrating.
What is intensity?
Intensity is a measure of the power, or energy per second, of a sound wave as it vibrates.
How are amplitude and intensity similar?
Amplitude and intensity both affect the volume of a sound wave as it is perceived by the ear.
What is the relationship between amplitude and frequency?
Ideally, there is none. A strict change in the frequency of a pitch will not change its amplitude, and vice versa.
Describe the amplitude and frequency of a note that is low-pitched and loud.
The low pitch is a result of a low frequency, and the loudness a result of a high amplitude.
What unit is used to measure amplitude?
From what scientist does the decibel take its name?
A decibel is one-tenth of a bel, which is named after Aexander Graham Bel..
What does a measurement in decibels indicate?
A measurement in decibels gives the ratio between the intensities of two different sounds
What is the decibel measurement for the human threshold of hearing?
Why is the measurement of 120 dB significant?
An amplitude of 120 dB is the human threshold of pain.
What does the term "dynamics" refer to?
Dynamics describe the different volumes in a piece of music such as forte or pianissimo.
What language is used for indicating dynamics in music?
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
pianissimo, piano, mezzo piano, mezzo forte, forte, fortissimo
What is the difference between a crescendo and decrescendo?
A crescendo indicates a gradual increase in the volume of music; a decrescendo indicates a gradual decrease in the volume of music.
What is timbre?
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."
What are harmonics?
Harmonics, or overtones, are the pitches above the fundamental that occur naturally when a sound is produced.
what is the interval between a fundamental pitch and its first overtone?
The first harmonic, or overtone, is exactly one octave higher than its fundamental pitch.
What type of sound does a sine wave represent?
A sine wave represents the sound wave of a note with no overtones.
What sort of wave is used to represent a pitch that is heard with only odd overtones?
A square wave.
What sort of overtones are present in a sawtooth wave?
A sawtooth waveform is used to indicate a pitch that is heard with all of its overtones.
Name three factors that affect the sound spectrum of an instrument
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.
What cause interference?
The overlap of multiple simultaneous sound waves
What is constructive interference?
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.
What is the product of constructive interference?
Constructive interference results in a sound wave with an amplitude equal to the sum of the amplitudes of its component waves.
What causes destructive interference?
Destructive interference occurs when two interacting waves are "out of phase": they are not perfectly aligned.
What is the result of destructive interference?
Destructive interference fully or at least partially cancels out the amplitudes of its component waves.
What causes beats?
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).
What determines the number of beats per second created by two interfering sound waves?
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).
within the key
Which scale degrees correspond to major triads in a major key
which scale degrees correspond to minor triads in a major key
why does the dominant triad resolve to the tonic
it contains both the fifth scale degree and the leading tone
harmonies that pull to the dominant chord
on which scale degrees are the most common predominant harmonies based