The Southerners of Vietnam refer to this instrument as Dan Kim. Dan Nguyet has two strings and the resonator resembles the moon, that is probably why it is named Dan Nguyet, which means moon lute.
The strings were traditionally made of silk but are today normally made of nylon, which can be strummed with either finger or pick. The Dan Nguyet provides a mid-range pitch in traditional orchestras and is played in short, melodic passages. The instrument's use has varied from province to province, but in the south it's been used to accompany Cai Luong opera.
According to ancient carvings, the moon-shaped instrument appeared in Vietnam in the 11th century. Intended to be played by men, the lute has maintained a very important position in the musical traditions of the Kinh people. Therefore, this instrument is widely used in their folk, court, and academic music.
The Dan Nguyet is distinguished by its pure and loud sound, as well as by its great capacity to express different emotional moods. Thus, it is heard at solemn and animated ritual concerts, funerals, or refine chamber music recitals. It can be played in solo, as part of an orchestra, or to accompany other instruments.
This instrument has quite an important role in Vietnamese traditional music. Due to its long neck and high frets, the Dan Nguyet is also used as an ornament.