Vibration accred by guitar is the big implies for us to hear different sounds. It is divided into two types of  rhythm: node and antinode. The vibration can propageande with our ears. Then the head will decide the vibration into sound.  Quick compression vibration generates high pitch. Low pith is produced by lower vibration.

The location where the fingers are put decides which kind of waves are created. If the middle point are stirred，odd wave will transer through the body of guitar. As people prod the edge part of guitar,  even wave will be produced immediately.

The wave type dépend on  four factors: length, tension, density, thickness. Most of guitars have the same characters of length and tension. Different sound results from various kinds of length and tension.

The space between overtones and other tones who have twice frequence as last one can be seperated into 12 small parts. They are called as an octave. Some instruments, like violin create infinite frequence of wave through the move of music wire.

When the wave frequence collide with each other, the beats are established through the osicillate wave. The guitar players make use this character to combine at least 2 kinds of instruments. Electrical guitars get the signal from playing. Susquently it transfer through wire and retrieved by speakers.