noun
arrangement of a traditional Japanese piece for shakuhachi, kokyū, koto, etc.
In traditional Japanese music, 外曲 refers to an arrangement of a piece originally for another instrument (often shakuhachi honkyoku) for instruments like koto or kokyū. Contrasts with 本曲 (honkyoku), the original piece.
See also: 本曲
この外曲は、尺八の本曲を箏用に編曲したものです。
This gaikyoku is an arrangement of a shakuhachi honkyoku for koto.