A se exhibited at the Tainan Confucius Temple
The history of the se extends back to early Chinese history. It was one of the most important stringed instruments to be created in China, other than the guqin. The se was a highly popular instrument during the Western Zhou and Spring and Autumn period. Surviving specimens have been excavated from places such as the Hubei and Hunan provinces, and the Jiangnan region of China. Other places include Jiangsu, Anhui, Shandong, and Liaoning. In Hubei, the tomb of Marquis Yi of Zeng (in the late 400's BCE) was a treasure trove of ancient Chinese instruments, including a complete set of bianzhong (bronze bells), se, guqin (plucked zither), stone chimes, and a drum. His musical entourage of 21 girls and women were also buried with him. By the Warring States Period, the early types of guzheng emerged, which was developed from the se. Thus, it is sometimes said that the guzheng is essentially a smaller and simplified version of the se (with less strings).
According to legend, Fuxi created the se. And so it is believed that by the time of the Xia Dynasty the se had already come into being. It is said that the word for music, yue (?), is composed of the characters si for silk (?) and mu for wood (?), and that it is a representation of the instrument.
The se has always been a high-brow musical instrument. As early as in the Zhou Dynasty, it was used to play ritualistic music for sacrificial offerings.
A similar instrument called seul, derived from the se, is still used in the Confucian ritual music of South Korea, which is performed twice per year at the Munmyo Shrine in Seoul. In Vietnam, the instrument was called s?t and used in a limited context along with the c?m (equivalent to the Chinese guqin).
The se's strings were made of twisted silk, in varying thicknesses. According to Lüshi Chunqiu on the number of strings that the se has: "A five stringed se, then became a fifteen stringed se. When Shun came to power, he added eight strings, so it became twenty-three." Another view suggests that the se started out with 50 strings. The Shiban later changes it to 25. "A big se has 50 strings, a middle se has 25." It also says that Fuxi created the 50 stringed se, called Sha whilst the Yellow Emperor reduced it to 25. There also is a "small se" that has half of the strings, 13 strings (like the Japanese koto). But archeological evidence has also unearthed se with 25, 24, 23, or 19 strings. The string number differs from place to place. The length is also different.
Unearthed se have similar construction, namely a flat long sound-board made of wood. The surface board of the se is slightly curved, and has three end bridges and one bridge at the head, plus four wooden posts for the strings to wrap around (some have two or three only). The posts also have patternation or decoration. The tail-end of the instrument has a long " ? " shopped opening for the strings to pass through. To string the instrument, one needs to tie a butterfly knot at the head of the string, strung through a bamboo rod, over the bridge at the head and over the main body of the instrument and over into the tail-end bridge into the instrument, out of the sound hole at the bottom of the instrument, over the tail-end and wrapped around the posts in four or three groups. The more modern form do not have the four posts and are instead strung a bit like the guzheng.
Although both are ancient zithers, the guqin and the se are different instruments in their own right.
There are very few players of the se, which largely became extinct during ancient time, although it is survived in the guzheng. The only notable se player in the 20th century was Wu Jinglüe, who was primarily a guqin player. There are also very few surviving examples of musical tablature for the instrument, a majority existing in qinpu (tablature for the guqin) in which the se was used to provide accompaniment for the qin.
Recently, there has been a revived interest in the se, with some musicians studying it. There are also a few factories that make a modern se using nylon-wrapped metal strings, though the instrument needs to be properly researched using modern mediums for it to be fully acceptable as a playable instrument for general musical purposes.