Playing the fast bow with the erhu is a very difficult skill. Where is the height, where is the difficulty? Although the bow is sharp, the sound is full, and the string is flexible, but without the graininess, it lacks the texture of the fast bow, and it cannot be a high-quality fast bow. The formation of granularity has at least three elements.

Friction

The bow hairs must grip the strings tightly, as if they are glued to the strings, in order to increase the friction. Only in this way, the sound will be strong, tough and clear. This is a prerequisite for the formation of granularity. Some people pull the fast bow, the sound is not real and not hard, and there is no feeling of the head, so there is no graininess. The main reason is that the wiping force is not enough. The rubbing degree of the inner and outer strings should also be the same, and there should be no difference in the strength of the sound. Sometimes a light and fast bow is required, but the principle of wiping the string cannot be changed, and the grainy feeling cannot be changed. You can move the wiping point from the middle bow to the tip of the bow to enhance the right hand's control of the bow.

cooperation of two hands

In addition to the bowing of the right hand, the left hand also plays a crucial role in the formation of granularity. Relevant experts say that the two-hand coordination of the fast bow is two-point alignment. That is, the start and stop time points of a note's right hand rubbing and the up and down time points of the left finger pressing the string must be precisely synchronized and aligned, and no misalignment is allowed. Because speed is the primary factor for fast bows, fast bows need at least 120 beats. High-speed fast bows can reach 180 beats. If it is calculated at 180 beats per minute, 3 beats are played in one second, and one beat is only 1/3 of a second. There are two 8th notes or 4 16th notes per beat. To be completed in such a short time, each note only occupies 1/6 of a second or 1/12 of a second. It can be seen that the coordination and control of the time points of both hands requires how precise. Failure to achieve this level of precision affects granularity. The fast bow requires the left hand to press the strings firmly and elastically. The flexibility of the left hand to press the strings and the speed of lifting the strings are generally not as fast as the speed of the bow. Pulling the bow and pushing the bow is just one action, while the left finger requires 2 to 4 actions, and it is necessary to change fingers and handles, so the action of the left hand is more difficult than that of the right hand. To eliminate the time difference of the left hand lag, only hard practice.

High relaxation of both hands

High-speed fast bow, almost to the limit of finger movement. The movement of both hands can be said to be a subconscious conditioned reflex. If there is no high degree of relaxation, there is the slightest tension, and the flexibility and sensitivity of the hands cannot be exerted. If a single note goes wrong, the fastbow's grainy chain will break. The relaxation of the right hand ensures the fast and stable movement of the bow and the flexibility of the wrist, which can maintain the balance of the force in the conversion action of pushing and pulling the bow, resolve the inertia of the left and right movement of the bow, and overcome the inertia of rapid string changing; the relaxation of the left hand, It can ensure that the fingers can press the strings easily, the intonation is in place, the change of the handle is accurate, and the action lag is eliminated. Therefore, only in the case of a high degree of relaxation, the movements of the two hands can be highly coordinated and precise. The foundation of fast bow lies in the training of basic skills. The fast bow section of a piece of music is the installation and combination of fast bow techniques. After dozens or hundreds of rehearsals, the technique can be finalized and become an image stored in the player's mind, which can be recalled and displayed naturally at any time.