Western sound engineers' treatment of BM favours the noise pollution of concourses, lobbies, aisles and open shopping areas. In Japan even our silent shopping interludes aren't overlooked for audio stimulation. Surround sound was installed in American supermarkets in the mid 1950's reaching European strasse and high streets during the early 1960's. British background music evolved from Music While You Work, broadcast into munitions factories by radio during the second world war. Continuous tape machines with auto reverse or endless tape loops provided several hours of music. Today you can still rent an eight-hour CD and playback machine from Philips featuring mood music in several grades.