Single-string box zither of Vietnam (for Hornbostel-Sachs classification, see Chordophone). The đàn đoc huyen (đàn: ‘instrument’; đoc: ‘unique’; huyen: ‘string’; bâù: ‘gourd’) consists of a box without a base, formed by three wooden pieces (ngô đong wood for the soundboard, tulip wood the sides) of about 80 to 100 cm in length and from 9 to 12 cm in width. A flexible bamboo stem holds a gourd or an empty coconut shell for a resonator and is attached to one end of the soundboard. A steel string, often that of a guitar, is at one end tied to the bamboo stem, stretched obliquely along the soundboard and tied round a peg on the side of the box.
The instrument is put on the floor in front of the musician who holds it in place with his right foot. The player holds a 15 cm long bamboo stick like a pencil between the thumb and fingers of his right hand, and plucks the string with the bamboo stick, while the right edge of the same hand touches the string at vibration nodes, producing harmonics. The flexibility of the stem holding the gourd enables the musician to vary the pitch of sounds by pulling to the right or the left. The instrument is characterized by the exclusive use of harmonics and the variation of the tension of the string. Some musicians use a small plastic plectrum to pluck the string, creating special sound effects with tremolo technique reinforced by amplification.
According to a Vietnamese legend, a fairy devised this instrument for a blind woman so that its sound resembled the human voice. It is favoured by blind musicians who use it in epic narration. It was introduced to the Nguyen court (1802–1945) at the end of the 19th century and became an element of chamber music in central Vietnam at the beginning of the 20th century. After World War II it became a vehicle for virtuosity and received international recognition with performers from the 1950s and 60s such as Manh Thang, Minh Con, Thanh Chuong (d Vietnam, 1972), Nguyền HŨu Ba; Khac Chi and Pham Đuc Thanh (active from the 1970s); and the popular compositions of Đuc Nhuan. A new đàn bau, named hạnh phúc (‘happiness’) has been invented by Phan Chi Thanh, developing ideas from both steel and electric bass guitars.
The đàn bau can be played as a solo instrument, in duets or in an ensemble. Several works have been composed for the đàn bau and Western-style orchestra by such Vietnamese composers as Nguyen Xuân Khoát, Huy Thục, Nghiêm Phú Phi, Tran Quang HẢi and Trủong TrỦỏng (d 1989). The amplifier which has been recently added can diminish the noise caused by the contact of stick and string and can multiply the harmonics; but the instrument loses its intimate subtlety and mysterious character and only produces artificial sounds, similar to those of the Hawaiian guitar.
For illustration see Vietnam, fig.2.
TRaN QUANG HẢI