非常階段 (Hijōkaidan) are a Japanese noise collective formed in Osaka in 1979 from the city's underground experimental music scene, associated with free improvisation, noise and industrial soundscapes. Their work is characterised by confrontational, high-volume improvisation, tape and electronic manipulation and DIY releases, and over decades they have evolved through rotating line-ups, cross-genre collaborations and continued activity within the Japanoise underground.
