Guzheng is musical instrument originating in China approximately 2,000 years ago. It can be said that it is China’s national treasure.
Guzheng belongs to the family of fretless plucked zithers. It is the predecessor of the Japanese koto, Korean kayagum and Vietnamese dan tranh. Guzheng is not the same as guqin.
Most commonly, modern guzheng (after 1961) has 21 strings, tuned pentatonically (do, re, mi, so, la; D major) over 4 octaves. Very rarely guzhengs with lesser or greater number of strings are available: advanced players may use guzhengs with 23 or 26 strings. The strings are strung across the full length of the soundboard, over moveable bridges which transfer vibrations from strings to the soundboard and keep the strings from touching the soundboard. Their position, along with string tension, determines the pitch of each string.
Guzheng is placed horizontally on a special stand. Smaller guzhengs can be played on the musician’s lap. In its early history it was played while placed on the floor.
Strings are plucked by fingers of the right hand using 4 plectra (picks) attached to tips of fingers. Left hand is used to create half tones (as well as fa, ti) and tremolos (pitch bending), and sometimes also plucks the strings to compliment the melody. Some musicians use plectra on both hands, which is beneficial not only for plucking but also for protecting fingers of left hand from pain.
Some large volume instrument makers use ovens to accelerate the ageing process of the wutong in an attempt to increase profits. High-end luthiers consider this to be a deplorable practice, detrimental to the structure of the wooden grain.
Guzheng has a very large sound producing cavity, which is necessary for proper bass resonance. The top of the sound cavity (soundboard) is usually made from single piece of wutong wood (Paulownia tomentosa). Higher quality guzhengs also use wutong for the bottom soundboard. The wood must be well aged, in order to minimize deformation and shape changes over time, weather and humidity. In many cases wutong wood aged for 1 year is quite adequate for crafting an instrument, however, patience can add a great deal to quality of sound (and price). Some large volume instrument makers use ovens to accelerate the ageing process of the wutong in an attempt to increase profits. High-end luthiers consider this to be a deplorable practice, detrimental to the structure of the wooden grain.
There are many good reasons why wutong wood is the best choice for guzheng soundboard: Wutong is very light and strong, has excellent resonant qualities and produces the most desirable sound. Of course, it also is a tradition to use wutong. Many guzheng manufacturers source wutong wood from Lankao county in Henan province. Lankao county has dry climate, so ideal for wutong trees.
The best wutong wood for soundboard is from the center of the tree trunk, and from the side which faces south. North side of the tree trunk is not usable.
Lunlun Zou learned this trade secret about selection of wutong wood from China’s highest guzheng master Xu Zhen Gao: “The best wutong wood for soundboard is from the center of the tree trunk, and from the side which faces south. North side of the tree trunk is not usable.” Depending on the size of the tree, one trunk can provide enough wood for only 1-2 high quality guzheng sound boards. It is no surprise that guzheng instruments with highest quality wutong soundboard (and also properly aged and properly shaped) can be quite expensive.
Extremely critical in guzheng construction are bridges. Their design, shape, material selection and manufacturing quality are crucial for producing most desirable sound. Ancient guzheng bridges were made from ivory (as were other parts of guzheng). Today, bridges are usually made from rosewood or zitan wood.
Other parts of the guzheng are less sensitive to wood selection, but mostly for appearance reasons, zitan, rosewood, sandal wood and other rare tropical woods are used most often.