There are many types of vibrato, any method that uses the length or tension of the strings to generate sound waves can be called vibrato. Commonly used are rolling kneading, pressing kneading, sliding kneading, pulling kneading and so on. These four kinds of vibrato have their own characteristics and have their own timbre. Therefore, as an excellent player, it is absolutely necessary to master all of them. Because these vibrato combine to give the performer a wide range of possibilities in terms of timbre and expression, as well as a more individual sound.

It is worth reminding that although these four kinds of vibrato can be practiced separately, they are rarely used purely in practice. Because a good vibrato may be hand or finger based. So a certain component is prominent, but if there is no stiffness, each vibrato affects the muscles adjacent to it, and there will be other vibrato components.

Before learning to knead the strings, it must also be emphasized that in any case, pay attention to the tightness of the tiger's mouth on the piano bar, and be sure to avoid any way of pinching the piano bar forcefully. Therefore, if the tiger's mouth clamps the piano rod, it will inevitably cause great tension and paralyze the movement of the left hand. As an experienced teacher, it must be emphasized that the student's left hand must touch the piano rod very naturally and relaxedly, and then insist on Constantly reminding whether it is always in a relaxed state. This has a direct impact on its development height in erhu playing vibrato.

1. Rolling and Kneading

It swings the palm up and down to drive the first joint of the fingers to flex and extend. A method of producing sound waves by changing the length of the string by rolling the fingertips evenly across the pitch. Tumbling is composed of two action processes. The first process is to lift the palm up to straighten the first joint of the fingers and touch the strings with the surface of the finger. At this time, the sound is slightly lower than the basic pitch of the pitch; the second process is to lower the palm to bend the first joint of the fingers, The touch point rolls to the fingertips, and the sound is slightly higher than the base note. The two processes are repeated, and the fingers are rolled evenly across the phoneme, resulting in a vibrato that fluctuates up and down around the pitch base. In the beginning, the active point of the movement should be placed on the back of the hand, and the palm can only be moved up and down, but not fanned in and out. The wrist is an "axis" of movement, so the wrist must not be rigid. It is normal for the forearm to passively swing slightly up and down during exercise. However, some players use the forearm to drive the movement of the hand, which reverses the subordination of the tumbling movement, resulting in stiff movements and clumsy pronunciation.

Since the tumbling is based on the kneading of Western stringed instruments, it has a beautiful and smooth pronunciation. The frequency and amplitude of the vibrato are easy to adjust, and it is the preferred vibrato method for playing singing melodies.

2. Press the vibrato

It is a method of vibrating the strings by swinging the palm up and down to drive the fingers to produce different pressures on the strings to change the tension of the strings and emit sound waves. When pressing and kneading, the chord position of the fingers should be slightly lower than the pitch base. Its first action is the opposite of rolling and kneading, which is the hem of the palm, which drives the fingers to increase the pressure on the strings, so that the pronunciation goes from a slightly lower pitch to a slightly higher pitch. Decrease, so that the pronunciation falls back to a slightly lower note through the pitch base. In the beginner stage, it is recommended that some simple and effective basic movements should be performed without the instrument. First relax your body, and stretch out your left hand to touch your thumb with your index finger, and do some vertical and horizontal movements up, down, left, and right. This kind of exercise can make the muscle movements of beginners first establish a state of natural relaxation. After this movement is continued on the piano, the first joint of the fingers is straightened, and the touch point of the string rolls to the surface of the finger. At this time, the fingers have no pressure on the string. Then the first joint of the finger is bent, and the pressure on the string is increased while the touch point rolls to the fingertip, and so on and so forth.

The empty strings generally do not need to be kneaded. When the music needs it, the following three methods can be used: 

1. Use the wrist to drive the palm up and down, so that the piano bar shakes slightly to generate sound waves; 

2. Press one finger on the jin to do rolling and kneading, while slightly Pressurize to generate sound waves; 

3 fingers are pressed over a thousand pounds, slightly press the strings, and change the tension of the strings to generate sound waves. However, the vibrato sound wave of the open string only has fluctuations above the pitch base, and there is no fluctuation below the pitch base, so it is easy to cause high pitch. The solution is to tilt the strings slightly to the right, so that the sound of the empty strings is slightly lower, so that with the vibrato action, the intonation is normal.

3. Slippery strings

Sliding and vibrato is a unique vibrating method of Zuohu. It is a technique of changing the length of the strings to generate sound waves by sliding the fingers up and down around the pitch base on the strings. The symbol is "~~~~~~". There are two kinds of slippery kneading: small slippery kneading and large slippery kneading. Small slip kneading has a lot in common with rolling strings in the playing method. It also uses the up and down swing of the palm to drive the movement of the fingers. The difference from the rolling kneading is that the first joint of the fingers does not bend and stretch, but the fingers bend. Touch the strings with your fingertips, or even your fingernails. When the palm is raised, the fingers will slide up the pitch base to produce a slightly lower note; when the palm is lowered, the fingers slide down at the same time to produce a slightly higher note. , and so on. Sliding and kneading is a method of simply changing the length of the strings. Therefore, when playing, the fingers should touch the strings lightly, and try to keep the pressure on the strings balanced, without any changes, otherwise the unique flavor of sliding and kneading will be lost. The big slip rub is also called hanging wrist slip rub. As the name implies, the arm should be raised slightly, so that the wrist is suspended in the air, and the fingers are in a condescending state. The overall sliding on the piano bar; the sliding range of the fingers on the strings is relatively large, generally more than a second smaller around the pitch base. This kind of sliding and kneading is more common in Henan and Shandong-style music.

4. Kneading the strings

Kneading and kneading is a kind of kneading method in which the grasping force of the fingers changes the tension of the strings to generate sound waves. Its pronunciation is very tense, similar to the sound of crying, so it is mostly used in sad songs, such as "Jianghe Shui". When using kneading, the phoneme of the fingers should be slightly lower than the pitch base, the palm does not swing up and down, and the finger force is used purely to grasp and release, and the cycle goes back and forth, so that the tension of the strings continuously changes to generate sound waves. In order to make the fingers grasp the strings powerfully, the left wrist can be slightly slumped, and the palm of the hand can be pressed against the piano bar to form a reaction force opposite to the fingers, or several fingers can be pressed on the strings, especially the third and fourth fingers. Its own strength is relatively weak, and the above-mentioned methods should be adopted to increase the grasping force. Kneading is a special effect of vibrato method, if used improperly, it will affect the normal performance of the music.