While for an outside observer the harmonic innovations in bebop would appear to be inspired by experiences in Western "serious" music, from Claude Debussy to Arnold Schoenberg, such a scheme cannot be sustained by the evidence from a cognitive approach. Claude Debussy did have some influence on jazz, for example, on Bix Beiderbecke's piano playing, and it is also true that Duke Ellington adopted and reinterpreted some harmonic devices in European contemporary music. West Coast jazz would run into such debts as would several forms of cool jazz. But bebop has hardly any such debts in the sense of direct borrowings. On the contrary, ideologically, bebop was a strong statement of rejection of any kind of eclecticism, propelled by a desire to activate something deeply buried in self. Bebop then revived tonal-harmonic ideas transmitted through the blues and reconstructed and expanded others in a basically non-Western harmonic approach. The ultimate significance of all this is that the experiments in jazz during the 1940s brought back to African-American music several structural principles and techniques rooted in African traditions.