Filament was formed in 1997. This unit was a product of the endless and thorough analyses and examinations of listening and pronunciation as a testing ground of post-electronics music. With Sachiko M's original composition method as a core, it brings about sound experience that is totally different from music made by conventional "composition" or "improvisation," going beyond the auditory limits ranging from faint to roaring sound. So far, it performed in more than ten countries in the world and often stirred argument.