dan bau or
‘gourd string instruments’. They consist of a
trapezoidal sound box with a single string, stretched lengthwise along the
body of the soundboard, and a movable bridge with a wooden handle or tremolo
bar with half of a dried gourd, attached to one end of the sound box,
opposite of the tuning peg. The gourd covers the handle at the very point where the string is attached and contributes to the amplification of the sound volume of the instrument. Originally, its was made up from the top half of a
bottle gourd, though nowadays, the gourd is usually replaced with a more durable turned, wooden, bell-shaped cup. The Vietnamese word bau (bầu) means
‘gourd’, hence the instrument's name.