Closely associated with these cultural dynamics is the deep nostalgia of an industrial society, a nostalgia bred by rapid change. Obsolescence is a major reality in this kind of world of business turnover. Competitive machine processes are often out of date before they can be widely applied. Books are discarded before a fraction of the potential readers have heard of them. Hair, clothes, educational, and hit-parade patterns are switched faster than the young can grow into them. And record albums of the songs of 1930 or 1935 do a roaring trade as quaintly sentimental revivals of forgotten eras. A twenty-five-year-old can get wistful about reminiscences of ten years ago. In such a world the lasting qualities of horse opera with the fringe on top have great appeal.