Synthesis of overtone series

The pitch of an instrument is usually related to resonance. For example, stringed instruments or wind instruments can vibrate the air to produce sounds, and can also vibrate different frequencies at the same time to produce sounds with different frequencies. According to the standing wave principle, most of these frequencies are multiples, and these sound waves with different frequencies constitute overtone sequences.

Theoretically, the frequencies of overtones are 2, 3, 4, 5, 6, ... But according to the object characteristics of the medium, the vibration of the air medium often changes the original overtone frequency. But these features have little influence on listening except the accuracy of frequency. Therefore, it can be reasonably said that the frequency of overtones is an integer multiple of the fundamental frequency.

Extended data

The overtone principle: when a finger is pressed on the string (only touching the string without exerting force), the vibration of the string will be limited, and only the vibration with this contact as the node will be kept. If the contact is at 1/2 of the chord, the overtone frequency is twice the fundamental frequency of the chord; If the contact is at 1/3 or 2/3 of the chord, the overtone frequency is three times the fundamental frequency of the chord, and so on.

The third and fourth overtones have two contacts, the front contact (near the string pillow) is easier to play, and the back contact (near the bridge) is slightly more inclined to the bridge than the real sound, which is very troublesome to find. The higher the overtone series, the weaker the timbre, and closer to flute or falsetto when singing. Common overtones do not exceed the fourth overtone, and almost no sound can be made above the sixth overtone.

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