Sankyoku is the collective name for the three musical instruments: jiuta shamisen (shamisen, or sangen--a three-stringed Japanese banjo, for jiuta, or traditional songs with shamisen accompaniment), so (a long Japanese zither with thirteen strings), and kokyu (Chinese fiddle).
三曲（さんきょく）は、地歌三味線(三弦)、箏、胡弓の三種の楽器の総称。