Despite the central arguments of Greenberg, Adorno and others, "avant-garde" has been appropriated and misapplied by various sectors of the culture industry since the 1960s, chiefly as a marketing tool to publicise popular music and commercial cinema. It is now common to describe successful rock musicians and celebrated film-makers as avant-garde, the very word having been stripped of its proper meaning. Noting this important conceptual shift, major contemporary theorists such as Matei Calinescu in Five Faces of Modernity: Modernism, Avant-garde, Decadence, Kitsch, Postmodernism (1987), and Hans Bertens in The Idea of the Postmodern: A History (1995), have suggested that this is a sign our culture has entered a new post-modern age, when the former modernist ways of thinking and behaving have been rendered redundant.