Chinese bowed string instruments belong to the so-called huqin 胡琴 family ("barbarian stringed instruments"), hu 胡 meaning “barbarian” and qin “stringed instrument”. An instrument called xiqin 奚琴 (“instrument of the Xi people”), is believed to be the ancestor of the family, imported to China in ancient times from nomadic groups of Central Asia. Throughout the centuries, it gradually developed into many variants. Nowadays there are more than 30 types of huqin, but only a few are regularly used in the Chinese orchestra like erhu, gaohu, jinghu, zhonghu, banhu, gehu and matouqin.
The erhu belongs to the familiy of the huqin, the so called "barbarian stringed instruments", indicating its Northern association. It can be traced back to instruments introduced into China more than a thousand years ago. An erhu has two steel strings between which a bow of horsehair is permanently fixed. There is a small resonator body at the bottom that in the front is covered with snake skin (commonly python), and a long, round and fretless thin neck with two tuning pegs. Sound is produced by pushing and pulling the bow against the inner or the outer string. The two strings are generally tuned one fifth or one forth apart (D – A, C – A or A – D). The erhu’s mellow but plaintive tone is frequently said to be the closest sound to human voice. The erhu players make up the core of a Chinese orchestra just as the violinists do in the symphony orchestra.
The gaohu ("high-pitched huqin"), also known as the yuehu 粤胡("Cantonese huqin"), is an instrument originating from the erhu that was created by the Cantonese musician Lu Wencheng 吕文成 (1898 - 1981), in order to complement the erhu with a higher and brighter tone. Compared to the erhu, it has a slightly smaller sound box, commonly circular, and the strings are tuned a fourth or fifth higher. Skillful players are able to control its high pitch and use the gaohu to imitate the lovely chirping of birds. In a modern Chinese orchestra, there are fewer gaohu players than erhu players; the gaohu players usually sit closer to the audience, and the principal gaohu frequently serves as concertmaster.
The zhonghu ("alto huqin"), a bigger version of the erhu, was developed in the 1940s. Thanks to the large sound box and the tuning of the strings (a fourth or fifth lower than the erhu), the zhonghu produces a deep and mellow sound that blends perfectly with the sound of the erhu in an orchestra.
The jinghu ("Beijing huqin") is smaller than the erhu and its body is made of bamboo instead of wood, a feature that differentiates it from the rest of the huqin family. Like the gaohu, it has a high-pitched timbre that is similar to the voices of Peking Opera, in which it is a main accompanying instrument. The jinghu is rarely used in Chinese orchestra pieces.
The banhu ("wooden-board huqin") has a short, round sound box generally made from coconut shell and a wooden soundboard. It has a typical shrill and strident tone quality, producing the characteristic sound of the lively Bangzi Opera of Northern China. The banhu seldomly forms part of an orchestra, but is used from time to time as a solo instrument, interpreted by gaohu players.
Starting from the 1960s, many instruments have been developed in order to provide a Chinese equivalent to the cello, capable to sustain the sound of the erhu. Some of these experiments turned out to be unsuccessful and were soon abandoned, like for example the dahu ("large huqin"), a sort of very large erhu. After hundreds of experiments, in 1979, Yang Yusen 杨雨森 finalized the design of a hybrid bowed instrument known as the gehu ("revolutionary huqin") and its bigger version the di gehu (“bass gehu”). The gehu’s sound box is barrel-shaped and horizontal, with four strings stretched upon a small bridge. It is placed on the ground while the hole, covered by python, horse or lamb skin, faces to the left. Unfortunately, the gehu still proved to be weaker than the cello in tone and volume. As a result, most Chinese orchestras have opted for using another hybrid instrument of the ruan family, the laruan, or the Western cello instead. The renowned Hong Kong Chinese Orchestra relies on the gehu valuing its unique sound.
Under the experiments for creating an equivalent of the cello for the Chinese orchestras made after the 1960s is also the laruan (“bowed ruan”) and its larger version da laruan (“bass laruan”), which can be compared to the double bass. Most Chinese orchestras prefer to use the Western cello instead of the laruan, though there are notable exceptions like the China National Traditional Orchestra.
The matouqin ("horse-headed stringed instrument") is a bowed string instrument that is considered a symbol of the Mongolian nation. Under the Mongols it is better known as morinkhuur. It has a wooden trapezoidal sound box (traditionally the frame was covered with camel, goat or sheep skin) with two strings and two tuning pegs, and a long neck with a fingerboard and a carved horse head finish on top. The strings can be made from hairs, horses’ tails, or from nylon. Like many other instruments of the bowed string family, it has a bigger version, which is lower in tone and is called da matouqin ("bass matouqin"). The matouqin is famous for its complex fingering that is very hard to master. The tips of the index and ring fingers are used to press the strings inward, while the nails of the middle finger and last finger are used to push the strings outward to achieve different tones. The matouqin has a uniquely deep and mellow cantabile tone, capable to evoke the landscapes of the vast grasslands in the minds of its listeners. The matouqin’s music is listed under the UNESCO’s Intangible Heritage of Humanity.
From the Western orchestra, the Chinese orchestra borrows the cello and the double bass.