Is the sound quality of the instrument good? Does the instrument feel good when playing? Does the instrument look beautiful? This requirement is the same as that of erhu players for erhu and pianists for piano.

The shape of the guqin has changed with the times and aesthetics: it was round in Tang Dynasty and flat in Song Dynasty. In the Ming Dynasty, it began to be thin and petite, with simple lines, just like Ming-style furniture. The head and tail of the qin were rarely decorated with jade and patterns. The Tang and Song guqin, dating back thousands of years, are few that can survive to this day, but there are more guqin in the Ming Dynasty. The appearance and sound quality of the guqin made in the Qing Dynasty have deteriorated.

Whether the hand feels good or not, that is, whether the left and right hand movements are smooth and comfortable when playing. Whether the distance between the seven strings on the Yueshan Mountain and the Dragon Gum is normal, not too wide or too narrow. Whether the distance between the strings and the piano surface is appropriate, it cannot be "anti-fingered" because the distance is too large, nor can the empty strings "beat the surface" or the strings have "bad sound" because the distance is too small.

The height of Yueshan and the amount of "bow down" are the keys to whether it feels good or not. "Lowering the head", also known as "flowing water", starts from the shoulders of the second and third emblems, and gradually slopes down toward the head of the piano until it reaches Yueshan. The formation of the "head down" ensures that the height of Yueshan is guaranteed, and the fingernails of the right hand will not scratch the surface of the guqin when playing the guqin. But there is no certainty how much to "bow". How to get the height of Yueshan just right, both sides, is a difficult point in the process of picking the qin. If the harpist can't play the violin, it is difficult to reflect the subtle changes here. I once told a friend who was just learning how to make a violin: "Go up and down, go and bow your head". The meaning of this sentence is that if the piano on the piano table is turned out, the seventh string is on top and the first string is on the bottom, then the net height of Yueshan at the seventh string on the top should be 0.7 cm. The net height of Yueshan at the string should be 0.8 cm. Because the height of Yueshan increases due to "lowering the head", the net height of Yueshan can only be measured after "lowering the head" (a straight ruler is stuck on the surface of the piano, and the head is placed on Yueshan, and the net height of Yueshan can be measured). According to this formula to deal with the height of Yueshan, you can play the piano without "resisting the finger", and without the empty string and the sound.

Compared with other musical instruments, the requirements for timbre are more diverse and more complicated; it is also related to the different aesthetic preferences of piano players. The bad sound quality lacks the beauty of the rhythm that the guqin should have, like the "wooden box sound", or the lack of vibration of the "board sound" of the body, these are the sound quality that the players do not like.

The formation of sound quality is caused by a combination of factors, and a common structural or material element should not absolutely correspond to a certain sound quality result. For example, the sound box of the piano body has a large space, the sound quality may be empty, and there will be a lack of charm; on my "Qiu Lai" piano, the space in the middle of the body is larger than that of ordinary pianos, but the sound quality is strong, not empty, and not a "wooden box". Voice. Some newly made guqins have the same panel thickness, and some have good sound quality and charm; some lack vibration, and only emit a "board sound" without charm. How to find out why the sound quality is good or bad, and analyze various factors such as material, structure, paint, etc., must have a comprehensive and comprehensive concept, and cannot be sloppy and make assumptions.

The difficulty of guqin production is precisely because of these various and uncertain factors, and factors without specific data are at work. The qin practitioner can only rely on experience and feeling, grasp the synthesis of various factors, and make a guqin with excellent sound quality and good feel.

"Broken grain" is the aging crack in the paint on the old qin body left over from the Ming Dynasty and before the Ming Dynasty. The old qin with broken lines not only has the vicissitudes of time in appearance, but also the sound quality will become simple and old.

The new qin has no broken lines, but with the good old psychology of the players, some qin players also made "fake broken lines" on the new qin. The production of false broken grains may involve changes in sound quality, because one of the methods in the production of various false broken grains is to properly bake the piano body after completion to artificially bake broken grains. This baking will also cause part of the lacquer to peel off the wood, changing the sound quality, usually the sound quality will become old and closer to the old piano. At the same time, the mottled broken lines increase the beauty of the appearance of the instrument. There are many ways to make fake broken lines, and some are displayed on the surface of the piano through chemical methods.

The choice of the body wood: the top of the guqin is made of paulownia or fir, and the bottom plate is made of catalpa. The paulownia wood of the panel should be Qingtong, but now it is often replaced by the easily available paulownia. Using the old fir beams of the demolished century-old house as the panel material is a practical and successful method. If new materials are used, the juice contained in them must be removed to make the vibration of the piano materials jump. It is necessary to "age" and "old" the texture of the wood in a short time. This kind of piano material treatment is also introduced in the Ming Dynasty piano score, that is, soak the new piano material in the pond for a period of time, then pick it up and dry it. It is conceivable that this method is extremely time-consuming and labor-intensive. Guqin workshops and factories with a certain scale must take a long-term view, constantly buying old wood such as old fir and beams, and at the same time accumulating a certain amount of new wood, allowing them to "age" year after year. Aging is the change in the fiber structure inside the wood, so that the manufactured guqin emits an old-fashioned sound, that is, an old-fashioned sound.

Among several factors related to sound quality, the selection of Yueshan and Longgu is also extremely important. The strings are directly mounted on it to vibrate the body, and a hardwood material with a compact structure must be used. The best is red sandalwood, but red sandalwood is expensive and rare. Others such as Chenglu and Jiaowei can be replaced by ordinary hardwoods.

The use of lacquer ash: The "putty" blended with raw lacquer and antler cream is lacquer ash. The thickness of the antler cream blended into putty, the ratio to the raw lacquer, the thickness and frequency of applying the piano body, and the drying time after each application are all necessary knowledge and experience for piano players.

The color of the piano body: mainly black, or red and black, it should have a heavy feeling. Avoid frivolity, avoid fancy, avoid drawing.

The volume of the guqin played indoors or in the study room is inherently low, and no one who plays the guqin regards the volume as good or bad, or likes or dislikes it. Compared with other instruments, the volume of the guqin, which is very loud in the production of new qin, is still very small.

For accessories such as qin emblems, qinzhen, and wild goose feet, qin practitioners usually no longer make them individually, but go to those guqin workshops or factories with a certain scale to buy them, because it takes a lot of time to make a small amount.

Choice of strings: silk strings, steel nylon strings, rayon strings. The use of silk strings is a traditional practice. During the Cultural Revolution, the production of silk strings was discontinued. The Shanghai Conservatory of Music Musical Instrument Factory began trial production of steel nylon strings, and the production of steel nylon strings has not stopped. As for man-made fiber strings, they were developed by Master Dai Chuang, a retired employee of the Musical Instrument Factory of Shanghai Conservatory of Music in recent years, and are now under the patented production of Xiamen Longren Qinfang.