The Ba [巴] and Shu [蜀] are two ethnic groups living in the Sichuan [四川] area since the ancient times. During the Warring States [戰國] era, the country of Qin [秦國] conquered their land. Soon, the music and dances of the Ba Shu people could be heard in the Qin courts and was so wildly popular that soon after, spread to the rest of the country as well.
Since then, the music of this area slowly absorbed influences from other cultures but at the same time, retained many of its original characteristics, giving us the unique sound colours of the music of this Ba Shu area.
Sichuan is an area flanked by Yunnan [雲南] and Guizhou [貴州] at the south, Tibet and Qinghai [青海] to the northwest, Gansu [甘肅] and Shaanxi [陝西] to the north and Hubei [湖北] and Hunan [湖南] at its eastern borders. This area is mountainous and has been one of the origins of the ancient civilisation of China. These factors affect the types and characteristics of the music from this region.
Mountain songs are extant in this area. The mountain songs can be grouped into gaoqiang [高腔] mountain songs, pingqiang [平腔] mountain songs, and aiqiang [矮腔] mountain songs. Gaoqiang mountain songs have a wide melodic range with plenty of leaps within the melodic movement. The rhythm is free and varied as can be found in the following piece of music and it is often sung with a mix of chest voice and falsetto.
Pingqiang mountain songs has longer phrases in the beautiful melodic line and the range is not as wide as that of the Gaoqiang mountain songs. Its rhythm is also somewhat free.
Aiqiang mountain songs have smooth flowing melodic line with a much narrower range and less leaps and skips within the melodic movement. There is more regular rhythm and phrases are short and regular and it is sung with the chest voice and not falsetto.
In the folk songs of the Ba Shu area, the note yu is frequently an important pitch centre. There are a few variants: "Shu" mode [蜀調] otherwise known as the "narrow-yu step-wise progression"; "Ba" mode [巴音] or "small-yu leap-wise progression".
In the Shu mode, 2 three-note groups are prominent, hrars and ghra. Sometimes only one group can be found within a folk song, sometimes, both groups are used equally. There is more smaller step-wise movement in this mode hence the music tends to be smoother, gentler and more delicate-sounding.
In the other mode, the "Ba" mode, hrard are the main skeletal notes. In this mode, movements of leaps and skips are much more frequent and the music hence sounds brighter, brasher, and forceful.
The melodic movement of folk songs are very much influenced by the linguistic characteristics of an area. The Sichuan dialect has close pronunciation with the northern dialects such as Mandarin, but its tonal inflections are very different. This led to the unique modes that have evolved in the folk songs of this area.