Please enable JavaScript.
Coggle requires JavaScript to display documents.
MUSIC (Properties of a sound wave (Frequency = The number of cycles per…
MUSIC
How are sound waves produced?
Sound is the rapid cycling between compression and rarefaction of air.
Three vital components that a sound must involve
something moves
something transmits the results of that movement
something (or someone) hears the results of that movement (though this is philosophically debatable)
Sound waves are produced by vibrations.
The vibrations are caused by air molecules hitting the eardrum. These vibrations force molecules in the medium to bump into each other, thus transferring the vibration across the medium.
As mechanical vibrations require molecules to transfer energy, sound waves cannot travel in a vacuum.
Music and mathematics: daily examples
Programming
Software and production of electronic music
Sonar technology
Using soundwaves and their interaction with the surrounding environment to determine location
MUSIC THEORY
Time signatures
How many beats per measure, composers would have to account for the amount available when inserting notes and rests
Octaves
For example, the A (440 Hz) multiplied by 2 = 880 Hz is also an A, but just one octave above.
If the goal was to lower one octave, it would be enough just dividing by 2.
We can conclude then, that a note and its respective note have a relation of ½.
Intervals
Pythagoras' experiment with playing with a 'stretched' string
Definition of a Pleasant Harmony: Show divisions of mathematical ratios 1/2 and 2/3
The tritone interval, for example, was obtained in a relation 32/45, a complex and inaccurate relation, factor that makes our brain to consider this sound unstable and tense.
Subdividing the string to produce intervals and chords
Scales
Subdividing the original note from a stretched string to determine a perfect chord
The Chinese finished their divisions getting the notes C, G, D, A and E, taking B aside, which became the pentatonic scale
Chromatic scale: Multiplying the frequency on the note by the number 1.0595 we would arrive in the next semitone.
Example:
246.9 x 1.0595 = 261.6 Hz (the note C).
Multiplying the frequency of B by 1.0595 we will have:
Frequency of C: 261.6 Hz
Frequency of B: 246.9 Hz
Piano makers put the form of a logarithm graphic in the piano body, because log2 would provide the best sounds
Properties of a sound wave
Frequency = The number of cycles per second (measured in Hz)
Period = The time duration of one cycle (the inverse of frequency, P =1/f)
Cycle = One repetition of a wave's pattern
Wavelength = The length of one period of a wave
Amplitude = A measure of a wave's change over a single period