Comparing the individual sounds, you may notice that one in eight sound impression, homogeneous with the first, the ninth – the second, the tenth to the third, etc. This is because the number of oscillations in the eighth sound exactly two times bigger than in the first. Therefore, musical sounds are combined in an octave. In each octave 8 sounds, including 7 different height and 8 – octave – as if the repetition of the first in a new height. Middle C corresponds to 440 vibrations per second, a la the second octave – 880 vibrations per second.
Ancient scholars, beginning with Pythagoras, tried to “harmony with algebra believe”, studied musical intervals, discovered the mathematical relationships between the individual sounds. In music, there is special unit intervals – semitone and tone. Depending on experience, which we produce on intervals, they are divided into consonances (from the Latin consonantia, concurring sound) and dissonances (from the Latin dissonantia, sound apart). Consonance creates an impression of peace, completeness, euphony; dissonances same sound sharper, harder, they demand the continuation of the melody, the transition in consonance.
Various effects on our psyche intervals depend on the ratio of the number of vibrations per second sounding body, reproducing every sound interval. Thus, the sound component with the octave interval gives the number of oscillations in the two more times (the first octave – 261 oscillation per second, while the second octave – 522 oscillations per second), so that both sound waves coincide sounds. Conversely, in an amount of difference of the oscillation in the sounds that make up a small interval so small (the first octave – 261 oscillation per second, and C sharp – 276 cycles per second), resulting in this discrepancy sound waves do not coincide, creating the impression jumble and sharpness sound.
The Sound of Music is always organized in a certain sound systems. The greatest civilization and national cultures created their own sound systems. Fugue by Bach, Beethoven, Tchaikovsky, Shostakovich quartet and even a song from the cartoon, penned these days – all these very different time of creation, the genre, the size of the works written in one sound system. While ancient Greek music was created under the laws of another sound system, the Chinese – it is also completely different.
The foundation of the sound system – scale. The system is characterized by a number of sounds in the range of one octave and the relation between them. For example, traditional Chinese, Mongolian, as well as Scottish, Irish music is built on a pentatonic scale, that is the basis of this sound system is a scale containing five sounds (do-re-mi-sol-la-up). In this scale are missing semitone intervals, and the intervals are a half pitch. There are also such “sophisticated” sound system – Indonesian – where the octave is divided into 22 parts.