Beginner Lessons
Sound As A Physical Phenomenon
Sound as a physical phenomenon: scale, octave, name of sounds, tone, semi-tone, keyboard, enharmonic, octave names.
Sound is a natural phenomenon caused by oscillatory movements of air elements or other surroundings. These fluctuations in the air form sound waves, which are captured by ear. As a result, a certain feeling arises - sound audibility.
In our lifes we hear different sounds: the noise of rain, wind, the machine engines, birds singing, the sound of musical instruments, etc. All of them fall into noise and musical. Music sounds, in contrast to the noise, has certain definite characteristics: height, duration, timbre, the volume.
The height of the sound depends on the frequency of vibration, in other words on the number of oscillations per second. The more of them, the sound is thinner, faster, lighter, in other words - higher. The less oscillations, the heavier the sound is - lower. The number of fluctuations, in its turn, depends on the elasticity of a sounding body, such as the string tension (the more the string, is taut the higher the sound is), as well as its length and thickness (the longer and thicker the string is, the lower the sound it produces).
The length of sound depends on the length of fluctuations of sounding body. Timbre (sound coloring) depends on the number of overtones, accompanying each sound. The volume depends on the amplitude of fluctuations (the greater the amplitude the louder the sound).
All music sounds are located in a sequential ascending or descending order form the scale. If we compare with each other all sounds of the scales, we can make sure that each and every one of them at some distance higher or lower has a corresponding sound. These fusing sounds share the same names. The minimum distance between them is called octave.
Octave is divided into 12 sounds within an equal distance - semi-tone. Of the 12 sounds only 7 have names: C, D, E, F, G, A, B (Latin letters are used for the notation of chords and music). These seven sounds are the major steps of a scale. The distance between them is not the same between E and F, and C and D – semi-tone. The other main sounds are intermediate, and the distance between them is two semi-tone known as the whole tone, or simply - tone.
The keyboard is vividly demonstrates this system: white keys are the basic sounds, black keys are supported.
As we can see the keys are the same in each octave.
To raise or lower the sound the alteration symbols are used:
(sharp) - semi-tone rise.
(flat) - Loss of semi-tone.
(natural) – canceling of sharp or flat.
Thus, the same sound may be called differently. For instance the sound between of the C and D: C sharp or D flat. This phenomenon is called enharmonic.
