The thumb only acts as a fulcrum, and it is not hard at all.
As you know, people are masters. They have been trained for many years to crawl around with their fingers dexterously. Masters don't crawl around with their fingers dexterously from the beginning. You keep practicing for a long time, and your fingers can crawl around skillfully.
There is a very authoritative concept about the attention of holding the piano in the left hand: Careba's concept of left hand relaxation. Please have a look first. You can ask me if you don't understand.
First, the natural hand shape
The beginning is the completion of skills. If you don't know what your natural hand is at the beginning of the first lesson of learning guitar (that is, relaxing your hand) and use it correctly, then all the exercises of your left hand will be a series of struggles, and you will be farther and farther away from relaxing. Even by an unnatural hand shape that has been used for a long time, it is impossible to find its original natural appearance and develop its infinite possibilities in guitar skills; Then the left hand will be restricted by the fingerboard, and it is impossible for the left hand to be liberated from the fingerboard and move freely on the fingerboard.
2. Natural hand prototype
What is a natural hand shape? When our left hand droops naturally, the appearance of no force at all is the starting point of our left-handed guitar practice. Once you can clearly identify it, keep relaxed and put this natural hand shape on the fingerboard, which is the correct way to practice with your left hand. It is a very important concept to put the natural hand shape on the fingerboard. The common wrong method of exerting force on guitar's left hand is to "hold" the fingerboard with the strength of the chin. As a result, the thumb at the back of the neck must be opposite to the four fingers on the fingerboard, and the power of fingers actively pressing strings (in the wrong way) comes from the chin. The average Zhang Liwei of one string is 7 kg, and the average tension of six strings is about 42 kg. It is impossible for a jaw smaller than an egg to bear the music of a concert for an hour. If a person knows the correct usage of his left hand, he can immediately judge whether his left thumb is bent. If the thumb of the left hand is bent, then his thumb must be firmly pressed against the neck of the piano, and the other four fingers on the opposite fingerboard must be balanced with greater strength. The result of the vicious circle of finger strength wrestling is that it completely violates the relaxation of the left hand and the development of skills. If you really see that the wrong method of actively clamping the fingerboard is a dead end, is it possible to have another method of pressing strings, which can make the fingers rest passively and completely unload the strength of the thumb and jaw?
Third, relax the use of hand shapes.
First of all, we should notice that when we play the piano, we can naturally "put" ten fingers on the keys in a relaxed state, without the help of the jaw and thumb clamp. So when we put the guitar flat like a Hawaiian guitar, the fingerboard of the guitar is facing up, just like the keys of the piano. At this time, can we gently put the five fingers of our left hand on the fingerboard like playing the piano (keeping a natural and relaxed hand shape)? You will directly notice that when you press the strings with your fingers, the thumb and the other four fingers are opposed to each other, and there is no such thing as pinching the fingerboards together. The chin and thumb are completely at rest, as are the five fingers on the fingerboard. This is the first step to free the left hand from the bondage of the fingerboard. Then, when the guitar is placed on the left big foot in a standard playing posture, the fingerboard is vertical to the ground, and the four fingers that remain relaxed are also "placed" on the fingerboard. Although the thumb is at the back of the neck, it does not add any strength to the neck. So if you put your left hand on the fingerboard, your neck will tilt towards your body, and your body will tilt away from your body. At this time, the balance of the guitar depends on the weight of the right arm on the side plate.
4. The relationship between hand shape and guitar fingerboard
The relationship between hand shape and guitar fingerboard can be illustrated by puzzles that everyone played as a child. The fingerboard of a guitar is like the bottom of a puzzle, and the natural hand shape of our left hand is a puzzle. There are basically three spellings on the fingerboard:
First, when the relaxed hand shape is placed on the same string, the fingertip connection line of 1 finger and 4 fingers is parallel to the string, which is called a straight hand shape.
Two. Put the relaxed hand shape on different strings, and the fingertips of 1 finger and 4 fingers are perpendicular to the strings, which is called a cross hand shape.
Three. When the relaxed hand shape is placed on different strings, the fingertip connecting lines of 1 finger and 4 fingers are obliquely crossed with the strings, which is called the comprehensive hand shape (between the vertical hand shape and the horizontal hand shape).
5. The sense of spatial positioning of wrists and arms
Pay special attention to the correct method of puzzles. There are large and small squares. As long as the angle of wrist bending is adjusted, the fingers will naturally open and contract, and the fingers are in a relaxed rest state regardless of opening or contracting. The main characters who really put their fingers on the fingerboard are wrists and arms. Fingers are in a passive state of natural relaxation from beginning to end, and the jaw and thumb are not forced. As long as the natural hand shape (vertical, horizontal or comprehensive) is brought above the position where the string is to be pressed, the remaining work is the small string pressing action of the fingers of the left hand (the only active action of the fingers: pressing the string downwards without lifting the string upwards, because the force of pressing the string downwards is released, the fingers of pressing the string will automatically return to the original hand shape ready to relax). Preparing all kinds of relaxing hands in advance is the secret of relaxing the whole left hand. The development of the whole left-handed technology is to find out all kinds of relaxing hand shapes you have and put them in the ready position on the fingerboard. The protagonists who control these hand shapes are wrists and arms. Training wrists and arms to push or pull fingers to the ready position with natural hand shape is the ultimate goal of the development of left-handed technology. A well-trained wrist and arm will have an intuition beyond rational understanding. It is absolutely impossible to make a mistake when you bring your finger to the position where you want to press the string accurately and completely, because as soon as you feel that you are about to lose your relaxation (fingers are out of passive rest), or any finger is not brought to the correct position, your wrist and arm will automatically reset and return to the relaxed feeling and correct position. The intuitive ability of this sense of positioning will increase day by day after being honed and developed in every piece of music, and the wrists and arms will become very sensitive to space. Even if you don't practice the piano for a long time, the skill of your left hand will not be greatly reduced, just like once you learn to ride a bike, even if you don't ride it for a long time, once you get used to it, you can ride it stably.
Step 6 move your left hand
1. Lateral movement: the left hand moves laterally on the same handle, from the 6th string to the 1 string, and vice versa. At this time, the thumb is fixed behind the neck of the piano to play the role of pivot finger. When the wrist arm is released from the bass string to the treble string, the wrist is retracted (the wrist bending angle becomes smaller); When the straight hand turns from the treble string to the bass string, push the wrist (the wrist bending angle becomes larger). It means that the wrist and arm push or pull the stationary finger at the same position with the thumb as the fulcrum, and position it above the correct position.
Two. Linear movement:
1. Part of the action: the thumb is fixed at the back of the neck (hinge finger), and the hand shape on the fingerboard brings the finger to a new position through the opening or contraction of the tiger's mouth (and the protagonist who controls the opening or contraction of the tiger's mouth is still the wrist arm). It is more efficient and safer to select some movements than to use the whole movement when changing positions back and forth quickly at close range.
2. Overall action: all fingers leave the neck and fingerboard, and use the wrist and arm to drive the relaxed hand shape to the new handle position. According to the position of the piano and the common factors of fingers, it can be divided into:
A. substitution: different fingers are taken away by wrists and arms and put into the same piano lattice.
B. displacement: the same finger is brought to different squares by the wrist and arm.
C. Jump: Different fingers are brought to different squares by wrists and arms.
From the above, whether it is vertical or horizontal movement, local movement or overall movement, it all points to the positioning ability of wrist and arm in space, which is the same as the positioning sense of the three basic hand types mentioned above.
Seven. The importance of scale
The best exercise to get a sense of wrist and arm position is weighing. First of all, simplify the right hand to hook the string with I and M, and concentrate on the left hand. Carlevoro skill workbook 1:24-tone scale. Including how to use the wrist and arm to correctly drive the fingers to present relaxed and accurate straight hand exercises in different strings and positions, as well as horizontal and straight movements, local and overall movements. (except substitution, because the scale will not repeat the same sound continuously, so substitution action cannot be used; But as long as you grasp the essentials of any kind of moving method-wrist-arm positioning, in fact, every moving method and feeling are exactly the same)