Vietnam has a long tradition of music and theatre that combines indigenous and foreign influences. The earliest known instruments are the frog drums of the Dong Son Period from around 250BC. This was followed by a millennium of immersion in Chinese cultural traditions which remains very apparent. In 981, after the reassertion of national independence, King Le Dai Hanh invaded neighbouring Champa and carried the royal court dancers and musicians back to his capital. Consequently traditional Vietnamese music is considered to blend Dong Son techniques with those of China as well as, through the Hinduised Kingdom of Champa, Indian musical forms. It is based a five-tone scale in contrast to the eight-tone scale generally used in the West.