Genres und Kategorien [G&K]]
A term that originally designated the instrumental B-side, or “version”, of a reggae single intended as a backing track for a deejay. The term came to be associated with the work of producers such as King Tubby and Lee “Scratch” Perry who, via studio effects, turned these versions into works of art in their own right.
(Source – Cox, C. and Warner, D. (2004) Audio Culture : Readings in Modern Music. Continuum.)