'The Inyjalarrku songs are a set of traditional songs from North-West Arnhem Land, Australia, composed entirely in spirit language. This spirit language is dream received, and used only in song. Like many such languages of the region, Inyjalarrku is semantically opaque (non-translatable). Non-translatability in Aboriginal song languages has been widely reported across Australia, with many variations. Inyjalarrku songs are stable, rather than improvised, and have a recognizable vocabulary of words and phrases which resemble the ordinary/spoken/everyday language of the region, but which are not associated with meaning in any conventional sense. Inyjalarrku takes on the aesthetic properties of spoken language in terms of phonemic and syllabic inventory, but adapts these to serve the unique requirements of language in song. By examining the nature of the language used in the Inyjalarrku songs, and comparing it to the spoken language of the region, Mawng, this article explores the nature and implications of the use of non-translatable language in Aboriginal songs.' (Introduction)