Theodor Adorno was a prominent philosopher who wrote on the aesthetics of popular music. A Marxist, Adorno was extremely hostile to popular music. His theory was largely formulated in response to the growing popularity of American music in Europe between World War I and World War II. As a result, Adorno often uses "jazz" as his example of what he believed was wrong with popular music; however, for Adorno this term included everyone from Louis Armstrong to Bing Crosby. He attacked popular music claiming that it is simplistic and repetitive, and encourages a fascist mindset (1973, p. 126). Besides Adorno, Theodore Gracyk provides the most extensive philosophical analysis of popular music. He argues that conceptual categories and distinctions developed in response to art music are systematically misleading when applied to popular music (1996). At the same time, the social and political dimensions of popular music do not deprive it of aesthetic value (2007).