Gehu (pinyin: gé hú) is a low-pitched stringed instrument with a louder volume and a wider range. In the 1950s, Yang Yusen (1926-1980) of the Shanghai Conservatory of Music created it on the basis of the erhu and absorbed the characteristics of other stringed instruments, so it is called Gehu. After continuous improvement, it has now become a bass-pulled string instrument with rich expressiveness.

The shape of the Gehu is different from that of the middle and low hus. It has four strings and a fingerboard. The drum is made of wood, covered with python skin, horse skin or sheep skin. The bridge is divided into the outer flat shovel horse and the inner umbrella horse. The vibration of the strings is transmitted to the python skin through the lever principle of the stroke of the inner and outer horses, and it does not directly bear the pressure of the strings.

The bow is the same as the cello bow, and it is played outside the strings, which is convenient for bowing. Because of the fingerboard, the sound is solid, and it is very convenient to press the strings.

In traditional Chinese instrumental music ensembles, because of the traditional pop polyphonic musical texture, there is no functional harmony, and there is no so-called "bass part". Therefore, various instruments mostly play melody, and there is no special one. An instrument that plays the role of bass and accompaniment. It seems that the traditional Chinese music aesthetics is the pursuit of high-pitched and bright timbre.

With the infiltration of Western music ideas into Chinese music and the establishment of Chinese orchestras at the end of the 19th century and the beginning of the 20th century, the traditional Chinese music ensemble, which is mainly based on the melody of Jiahua Unison, was gradually influenced by the mainstream harmony in Europe. The bass part occupies a very important position in Western harmony. Chinese music has been "Europeanized", influenced by the traditional functional harmony and orchestration of the West, but it lacks bass instruments that can support the entire band, forcing contemporary musicians Using Western bass instruments: cello and double bass.

But in a "Chinese" orchestra, using this "Western" (especially the appearance) instrument is always unreasonable. So musicians have developed a bass instrument that is completely, or at least looks like it was invented by the Chinese.