(* There is a view that the name of the song, Sujecheon is incorrect because many names like <Boheoja>.<Hyangdangyoju> etc. were temporarily used at every banquets or events in the past.
For example, in the 28th year of the reign of Soonjo(1828), the Hyangdangyoju, concerted music at Jagyeongjeon played when the king raises his glass was called Sujecheonjigok.)

It is one of the best classical court music having the characteristic of fermata style where the main melody of flute is played and other instruments, Daegeum, Sogeum, Korean fiddle, Ajaeng, etc. are continuously played to open the next clause and the movement of pomposo, magnificent and mysterious melody with slow calm rhythm.

It also had been played with the name, Bonghwangeum at the 1st UNESCO Music Festival held in France in 1970, and was openly recognized as the masterpiece in the world by being specially selected as the best musical piece in the traditional music field.

Mugo (drum dance) is one of the Korean traditional court arts performed with Dongdongok and Muaegok in Goryeo period.
"Mugo" was originated from the name of a drum made by Sijung Igon with pieces of board floating on the ocean when he was exiled to Younghae under the reign of Choongryulwang in the Goryeo dynasty.

There has always been changes in the performance of "Mugo" per each time period since the Goryeo dynasty.
The performance was made by Gisaeng playing drum, singing the song of Jeongeupsa and dancing to the song and the drum.
As the number of drums changes, the number of Gisaeng also changes. Depending on the number of drums, the name also changed to two-drum dance, four-drum dance and eight-drum dance.

The changes can be conjectured by the Huemugyeokodo(24th year of Sungjong/1493) handed down in the Akhakgwebum and the Mudo(28th year of Soonjo/1828) handed down in Jinjakeugwe.
And up until the middle of the Joseon dynasty, Jeongeupsa was sung as Changsa (traditional narrative ballad), but at the end of the dynasty (Soonjo?), Oeunhansi was written for Changsa.

The scale
Bitgarakjeongeup is closely related to the tune as shown in Akjochongeu and Hyungeumjo in the first book of <Akhakgwebum>.

Originally in Korean classical music, there were 7 tunes for each scale of Pyungjo and Gyemyunjo. Bitgarak is the next of the Segarak, that is the fourth tune. The keynote of Segarak is Imjong, and Namryeo is the keynote of Bitgarak.

(The current Sujecheon(Jeongeup) is composed of 5 notes, Namryeo, Hwangjong, Taejok, Gose, Imjong, and played with the formation of instruments, Korean flute, Sogeum, Korean fiddle, Ajaeng, Janggu and Jwago.)

Music form.

In <Akhakgwebum>, 'Mugo' has three tempos, Mangi(slow), Jungi(medium) and Geupgi(Fast). In <Gyeongookdaejeon>, it is Jeongeupigi which has same line of connection as Samgigok of <Jungwajung>), Samgi of <Jinjak>, Jeongang, Hoogang, Daeyup of <Cheoyonga> and <Manjeonchoon> or Manjo, Pyungjo, Sakjo, etc.
The current song handed down is composed of four chapters and the first, second and third chapters have 6 beats and the fourth chapter has two beats.
The second chapter is the repeat of the first, and the third chapter is changed in tune moving up four tunes higher than the first and second chapters, and the fourth returns to the original tune.
Sujecheon(Jeongeup) has the same fermata style as Sangyoungsan in <Samhyunyoungsanhwesang>.

The lyrics of Sujecheon(Jeongeup) is same as the one of Jeongeupsa. For Mugo, one of Hyangakjungjae (Korean traditional court arts), the lyrics called, 'Jegigajeungeupsa Hyangakjugigok.' are introduced in the record of music, <Goryeosa> as follows.

Likewise, there is a technique divided into Jeongang, Hoogang and Gwapyun and composed of three tempos, Mangi, Jungi and Geupgi.
Gwapyun appears to carry the characteristics of Hwandoo, and Kimsungo appears to be related to the tune of Kim Sun, master of Korean mandolin refered in the 6th book of <Hanrimbyulgok> as Kim Sun Bipa (Korean Mandolin).

Neverthless, it is noticeable that Aeu Darongdiri falling under Soyeop is omitted in Hoogang. Although there have been opposing opinions among the scholars on Korean literature; one view asserts that Hoogangjeon is correct, and the other says it shall be considered Hoogang Jeonjyeoje. However, in the musical aspect, there has been examples of Hoogang, but not Hoogangjeon, therefore, it seems Hoogangjeonjyeoje is correct.

Also, it has been decided that this type of musical form composed of three frames did not exist in the period of the Three States, and can not be retraced to the past before the middle of the Goryeo dynasty.

Study on Goryeosa, Akhakgwebum, Daeakhoobo, Hankookgayo (Yoonje Jo, Eulyoo Publishing, 1948), Yeoyo Jeonju(Joodong Yang, Eulyoo Publishing, 1947).