Wooden soundboard and sides and softwood as the middle. Metal string, machine tuner, electric pickup. Usually the instrument is tuned to one octave below middle C, about 130.813 Hz, but it can be tuned to other notes to make it easier to play in keys distant from C.
While the earliest written records of the dan bau date its origin to 1770, many scholars estimate its age to be up to one thousand years older than that. A popular legend of its beginning tells of a blind woman playing it in the market to earn a living for her family while her husband was at war. Whether this tale is based in fact or not, it remains true that the dan bau has historically been played by blind musicians. Until recent times, its soft volume limited the musical contexts in which it could be used. The dan bau, played solo, is central to Vietnamese folk music, a genre still popular today in the country. Its other traditional application is as an accompaniment to poetry readings. With the invention of the magnetic pickup, the usage of the dan bau spread to ensembles and also to contemporary Asian pop and rock music.