The dispute between Arnold Schoenberg and Heinrich Schenker—witnessed in Schoenberg's ironical remarks in the Harmonielehre and Schenker's vigorous polemics in the second volume of Das Meisterwerk in der Musik—was in the first instance a controversy concerning the significance of nonchordal notes (in the German, literally, notes foreign to the harmony), a subject that appears harmless enough. The dispute as such would be hardly worth examining if it revealed nothing beyond each antagonist's lack of understanding of the other and the failure of both to do justice to the subject about which they claimed to be speaking. But beneath the surface of a discussion about technical details is concealed a conflict of fundamental principles concerning modes of musical thought—modes of thought that cannot simply be reduced to the clichés of ‘progressive composer’ and ‘conservative theorist’.