Most bowed string instruments have two strings and some of them have three and four such as Saw sam sai (ซอสามสาย) . They have many tones colors,some are being well designed and Most bowed string instruments have two strings (e.g. Erhu and Gaohu), although some of them have four, such as the sihu and the gehu. Bowed string instruments mainly refer to instruments of the huqin category, which are used in solos, ensembles and accompaniments. Although bowed stringed instruments have a shorter history than other folk instruments, with beautiful sounds and rich expressiveness, they are deeply loved by all ethnic minorities in China. Moreover, they have various tone colors, some being well-designed and tender; some clear and bright; and some vigorous, cheerful, and melodious.