The tro Khmer (Khmer: ទ្រខ្មែរ) is a traditional bowed string instrument from Cambodia. Its body is made from a special type of coconut covered on one end with snake skin, and it has three strings.[1] Instruments are not standardized, and coconuts vary in size; however the instrument's sound bowl may have dimensions 16.5 cm by 14 cm.[2] In the past the strings were made of silk. By the 1960s, metal strings were in use, and the sound of the instrument changed, becoming sharper.[1]
The tro Khmer is closely related to a Thai instrument called saw sam sai.
The instrument may be related to the similarly shaped Indonesian version of the rebab, arriving there from Muslim culture, c. 15th century a.d.[1] A difference between the two is the number of stings; where the Indonesian rebab has two strings, the tro Khmer has three.[1]