Gagaku is the ancient court music and dance tradition of Japan, one of the oldest continuously performed orchestral music traditions in the world, encompassing purely instrumental pieces (kangen), music accompanying formal court dance (bugaku), and vocal repertoire, performed by a specific standardized ensemble of wind instruments including the sho, a mouth organ producing sustained chordal clusters, string instruments including the biwa lute and koto zither, and percussion.
The music is built on formal, highly structured principles distinct from later popular Japanese musical forms, favoring slow tempos, sustained tones and a deliberately restrained, ceremonial character suited to its use in formal imperial and religious occasions rather than popular entertainment. Gagaku is performed today both in strictly secular imperial court ceremonial contexts and within Shinto ritual at major shrines, where its association with sacred and ceremonial occasions, rather than everyday life, has helped preserve both the music and its associated dance forms in close to their historical form across many centuries, overseen for much of that history by a dedicated hereditary corps of court musicians responsible for the tradition's continued transmission.