According to the article on Ureuk (于勒) recorded in 'Akji' (樂志, music section) of Samguksagi (三國史記), there is the statement that King Gasil (嘉室王) had invented gayageum (plucked zither) after seeing musical instruments of ‘Tang (唐).’ It is clear that this statement could only appear after 618 when the Tang Dynasty was founded. Moreover, it is after September 644 that Silla's hyeon (prefecture) can be placed in Seongyeol-hyeon, which is the hometown of Ureuk. Since the name of Seongyeol-hyeon does not appear in the 'Jiriji' of the Samguksagi, it seems that the place name of Seongyeol-hyeon was used before 685 when the basic town name of the 'Jiriji' of the Samguksagi was decided. From the perspective of organizing music-related literature, if the writing of this document is regarded as Eumseongseo (音聲署), it seems that the birth of this record is related to 651, the point at which it was officially said that daesa (大舍) was placed in Eumseongseo.
 In that article, it is also found that gyego (階古) and juji (注知) were recorded as daenama (大奈麻, the 10th grade in the 17-grade system of Silla) while mandeok (萬德) as daesa (12th grade). However, in that mandeok 's official position corresponds to daesa of the Eumseongseo and a structure in which two superiors are located at the top can be found, it is believed that the prototype of the organization Eumseongseo was found even around the 550s, which is almost 100 years from 651. What had changed around 651 was that Silla music was documented, historicized, and systematized, judging from the point at which it was presumed that an article related to Ureuk in 'Akji' was written, as inferred earlier.
 In addition, paying attention to the fact that there are at least two people at the top of daesa , it is inferred the situation when the minister of Eumseongseo was jang (長) before being reorganized into gyeong (卿) in 687. In this regard, attention was paid to Seongcheon (星川), who appeared in 664. Considering the context of the narrative in which this character appears, Seongcheon is considered to be a character corresponding to daenama and has something in common with the cases of gyego and juji . Considering that the official position of gyeong in Eumseongseo corresponds to geupchan (級飡, 9th grade) to achan (阿飡, 6th grade), it is thought to give a clue that this is reorganized from jang to gyeong , and the position of the official has risen. It is believed to thank to the process of documentation, historicization, and systematization mentioned above. Therefore, gyeong of Eumseongseo, which was initially promoted thanks to the temporary expansion of music-related business, was able to maintain its prestige not only in the short term but also in the long term, thanks to such historical trends.