Violin overtones, also known as natural overtones. On the violin, when the strings vibrate as a whole, each part of the string also vibrates in segments simultaneously, producing a series of sounds, collectively known as overtones. Due to its transparent tone and imaginative and mysterious qualities, overtones possess unique expressive power. Because there are two different methods for playing overtones on the violin, overtones are divided into natural overtones and artificial overtones:

Natural harmonics 

This is based on the empty string sound (full string vibration), where fingers press the string at half, one-third, quarter, and other points of the full string to produce overtones of different heights using a bow. Due to the precise positioning requirements for overtones, the surface of the string that the finger lightly touches should be as wide as possible. For example, when the little finger presses the overtone, the larger finger can touch the string flat at the tip to increase the accuracy of the string pressing. When using a bow on the right, the contact point between the bow and the string should be selected in a suitable location close to the bridge, and the bow should be moved with lighter force and faster speed. It is important to avoid pressing the string or uneven speed and force during bow movement, as the contact point between the finger lightly touching the string and the string will leave or change slightly, causing the overtone to not come out or producing strange sounds.

Artificial harmonics 

This is based on one finger (index finger) pressing the real note (i.e. changing the vibration length of the string first), four fingers (little finger) virtual pressing the string, and playing different heights of overtones with a bow. When practicing, first, the fingers need to press the real note accurately, and the 1-4 fingers need to always maintain a pure fourth pitch (as well as pure fifth and third pitch overtones, which are less commonly used in practice), and naturally and accurately stretch and contract with the height of the handle. The requirements for virtual pressing the string and playing the bow with four fingers are the same as natural overtones.