Dan Tranh is a musical instrument of chordophonic family, plucking branch of the Viet ethnic group. Because Dan Tranh has 16 strings, it is also called Thap luc.

Dan Tranh has a long-parallelepiped shape. The frame of the instrument has trapezium-shape, 110-120 cm in length. The large end is 25-30 cm in width with holes and to hang the strings. The narrow is 15-20 cm in width with 16 tuning keys on the surface of the instrument. Its surface is made of wootung tree, 0.05 cm thick and arched.
The bridge of instrument or chevalet is put in the middle. It is used for hanging the strings and movable to tune the pitches. The strings are made of metal with different sizes. When playing, artist usually wears inger-nail plectrums on thumb, forefinger and middle finger to pluck. The finger-nail plectrum is made of different materials, such as metal, horn or tortoise-shell.

Its timbre is bright and clear and it expresses jubilant and pure melodies. Dan Tranh is rarely suitable with strong and moving characteristics. The range of Dan Tranh includes three octaves, from Do up Do³.

Dan Tranh is used to perform as solo and ensemble, accompany reciting poem, singing and take part in Tai Tu orchestra, Bat Am company, Nha nhac orchestra and general traditional orchestras.

According to Prof.-Dr. Tran Van Khe: Dan Tranh of Vietnam derived from Chinese zither and might be from the Tran dynasty or before that. People used it under 9 strings, 15 strings, and 16 strings. These strings are made of silk then copper and now steel. But through seven or eight centuries using it, Vietnamese people created a specific characteristic in fingering techniques, pressing and releasing, and scale. Dan Tranh has become a musical instrument bringing characteristic of Vietnam. Vietnamese people are very fond of using it and it is transmitted from generation to another over 7-8 hundred years, suitable with the aesthetics of Vietnamese people and expressing Vietnamese musical language clearly