A large number of variations from the text of the original German edition are explained in the body of this work or in foot-notes. In cases where the German editors were found to be in disagreement with the English manuscript in matters of opinion merely, the editor has chosen to let Mr. Thayer’s arguments stand, though, as a rule, he has noted the adverse opinions of the German revisers also. A prominent instance of this kind is presented by the mysterious love-letter found secreted in Beethoven’s desk after his death. Though a considerable literature has grown up around the “Immortal Beloved” since Thayer advanced the hypothesis that the lady was the Countess Therese Brunswick, the question touching her identity and the dates of the letters is still as much an open one as it was when Thayer, in his characteristic manner, subjected it to examination. This editor has, therefore, permitted Thayer not only to present his case in his own words, but helped him by bringing his scattered pleadings and briefs into sequence. He has also outlined in part the discussion which followed the promulgation of Thayer’s theory, and advanced a few fugitive reflections of his own. The related incident of Beethoven’s vain matrimonial project has been put into a different category by new evidence which came to light while Dr. Riemann was engaged in his revisory work. It became necessary, therefore, that the date of that incident be changed from 1807, where Thayer had put it, to 1810. By this important change Beethoven’s relations to Therese Malfatti were made to take on a more serious attitude than Thayer was willing to accord them.