As the long nineteenth century drew to a close amidst musical and social upheaval, three major anniversaries were celebrated for Haydn and Mozart – two centenaries of death and a sesquicentenary of birth in 1891, 1909, and 1906, respectively – against the backdrop of an evolving musicological climate beneficial to both. For example, distrust in the idea of musical progress, aligned with continued and increasing skepticism about social and political progress more generally in the decades either side of 1900,1 worked to their advantage as composers of century-old works and to Haydn’s specifically as the first of the Viennese triumvirate. For Donald Tovey in 1902, artistic and scientific manifestations of the phenomenon needed to be distinguished.