Beethoven’s op. 135, one of the last works he composed, is equally famous for its compositional clarity and for the inadequacy of previous editions. Theproblem lies in the surviving sources, for Beethoven’s autograph score contains a great many contradictions compared to his autograph set of parts. In 1827, after Beethoven’s death, the German publisher of the first edition posthumously ironed out these discrepancies as he saw fit, and later editions simply adopted his interventions. Rainer Caden