There are no cardinal rules in the bow technique

   The bow technique has been carefully studied over many centuries but there is no fixed rules. Of course the basics in the use of the bow is universally same but the high level of bow technique used by the world class performers use a unique way of using the bow that is extremely individual. This can only be superficially copied. For example, Milstein's style is based on the focus of the shoulder, whereas Perlman utilizes his big arms and hands in a chopstick style. Gidon Kremer creates a unique sound by using the whole bow in fast speeds. The way these great players include these techniques into their style does not mean that we can isolate these features and parody them to produce equal results: many other subtle factors are needed to make a sucessful performance and it may be to the detriment of the student to parody these features for the sake of emulating them. Although the variety is infinite, it is better for beginners to follow the text book basics in using the bow. At any level the infinite choice of the bow and the problems that follows with it will always exist. I always advise my students to find a bow technique that suits them the most. When great violinist play the exact same piece, they use different fingerings and bowings because they use what is the most comfortable and effective for their playing. Yet when advising a young player who cannot make an independent decision, one needs to be careful. Therfore it is important that the player is able to experience theoretically correct bowing/fingering and one that suits their physical features and is able to make a good decision in making the necessary adjustments themselves. If the student is critisised too heavily or put down too much, the student will not be able to find what is right for themselves and will increasingly lean on the teacher. Even if what they are doing does not work very well, the student should be encouraged to do better rather than critisised. In the past I have personally experienced that when I was constantly practicing a certain aspect of playing, the improvement seemed slow and unnoticeable. Yet when I practised with time and ease, I showed vast improvement and understanding. It is more so of young players who are constantly growing and changing. Same goes for adult students. If one diligently practices, one can show enormous improvements. At this point of a student's progress, the use of a mirror is important because one can monitor the angle of bow on the string as well as one's general posture.
   After having  first checked the angle of the bow, one should then feel the pressure within the bow at that point of the bow. We cannot know the sound that will be produced before playing and therefore must practise to rely on our tactile instincts. The problem occurs when all too often a player starts to play without any preparation of any kind. Therefore, one should check the angle of the bow, feel the pressure (or even just prepare the pressure in the air) and then adjust the speed accordingly. At first it takes a lot of mental effort and time but with pratice this whole process can become second nature as the reflexes will take over. It is essential that the metronome is used.
   We will now look at the problems that occur with bowing techniques. When spiccato bowing is difficult due to very stiff wrist, the first thing that needs to be worked on must be relaxing and releasing the tension in the wrist. Without the bow the wrist should be exercised consistently by turning it 360 degrees. Then the wrist should imitate brush-stroking motions by moving it in up and down movements. If these simple exercises were carried out consistently in any spare moments the student had (regardless of time and place) the stiff wrist will become more agile like a well-oiled machine. Of course the extent of the wrist movement depends on the speed of the spiccato bowing and as the speed increases the distance of the string and the bow becomes smaller. The wrist movement becomes more spring-like. Although the wrist is relaxed, it is important that the fingers that are holding the bow should be firm and not be too loose. It is easier to understand if one thinks of the finger tips as an extension of the bow. The first finger controls the direction and angle of the bow and therefore should not press the bow at all. Meanwhile, the last finger is very important as it controls the lever (the thumb) of the bow. A triangle is formed by the first, last and the thumb which predominantly controls the bow.
   Here, the issue of smooth change of bow will be discussed. This is a universal problem that any beginner comes up against. It is best to begin by asking the student to distinguish the different sound quality of a up and down bow and then asking them to make them sound the same. If the student cannot do this, he/she should diminuendo at the end of the bow. The rough quality of sound in the middle of the bow can be improved by using a metronome: start with a slow tempo and increase it to a fast one by counting. Also by placing a small sticker to indicate the middle of the bow the student can identify the distribution of the bow better, and therefore adjust the balance of the speed and pressure of the bow. The change of the bow or of the string should be so smooth that it is undetectable. When changing strings, the point of change on each string should be fixed so that the change is as smooth as possible. For example, when changing from G to E-string, the leap is very large. The two strings inbetween will not be touched if the point of change is decided upon.
   Another problem that performance can bring out is the change of fingerings. Players with large hands have a constant problem of pushing away the fingers in high positions in the E-string, like Perlman, whereas players with the opposite problem of small hands face difficulties in playing perfect fifths, chords, stretching for notes and wide intervalic leaps or shifts. One must adjust according to one's own physical limitations. But none of the above mentioned gets in the way of building up technique and experience. Great performers such as Kyung-Wha Chung has suceeded with hands a third that of Perlman's whereas Perlman is giving beautifully detailed performances despite his large hands. Chung has said that she uses the fourth finger constantly to give natural, expressive emphasis in her performance: it is important to use the relatively weak fourth finger to strengthen it instead of changing fingerings to accomodate and avoid the fourth finger. Therefore, in order to produce a performance where the fingering is not an obstruction to the music, no finger from the left hand should have preference over the others. To build a left hand that is equal in its use of the fingers, the student should practice scales and trills in three octaves. Each finger should anticipate the movement and be close to the string , ready to play. Economy of movement is important. The pressure of the fingers should be not too weak or too strong: one should make the adjustment by judging the sound.
   If the left hand is too relaxed there is not enough strength to articulate but on the other hand, if the hand is too firm, the player will experience pain. One can only find out through trial and error.
   Anything that is natural is beautiful. It is my belief that any movement that is the most suited to the physiche of the individual player is the most  natural. Music is a product of human nature, together with the rest of the arts, and that is the reason that it has been revered fever since the ancient times.