The gloom of the last few years cast its shadows even over my work, as you, who seek and recognise the living author behind his words, will not fail to discover; I trust that you will also find traces of the conscientiousness with which I have striven to perform my appointed task. You will agree with me in thinking that it would have been unadvisable to subvert the whole design of the book in substance and form, and that I must content myself with such improvements in matters of detail as would bring me {LIFE OF MOZART,} (xxvi) somewhat nearer to the end I had in view. It was, of course, my first endeavour to rectify such errors and remove such blemishes as had been observed either by myself or others, and I then proceeded to turn to account all the materials that had come to hand for the completion or enrichment of my narrative. I had become the fortunate possessor of copies of Mozart's complete correspondence, so far as I know it to exist. If, as I trust was the case, the extracts already before the public had been found useful and trustworthy, there could be no doubt that the completed version would render my narrative more accurate and lifelike. In addition, I had now Mozart's entire compositions, either autograph or copied, so that I could confirm my account and my criticism of each work by direct reference. Besides these efficient materials for the confirmation of my main authorities, I had received numerous separate communications, partly from friends to whom I owe much gratitude, partly from publications of the last ten years bearing upon my subject, some of which have been of great service to me. The most important aid, both to myself and to the readers of this edition, has been afforded by Ludwig v. Köchel's "Chronologischthematisches Verzeichniss sammtlicher Tonwerke W. A. Mozarts" (Leipzig, 1862). The necessity for such a catalogue had so strongly impressed me that I had resolved on compiling it myself, when I fortunately learned that Köchel was at work upon it. I was speedily convinced that it was in far better hands than mine, and it gave me genuine pleasure to afford it such assistance as was in my power. Unexampled assiduity, sparing neither sacrifice nor exertion, has produced a work which, from the completeness of its research and the accuracy of its execution, may serve as a model. A few addenda and corrections were indeed unavoidable: Kochel has himself indicated some (Allg. Mus. Ztg., 1864, p. 493), and you will find two or three trifling ones in my book. The fact that Köchel's catalogue contains a complete chronological and biographical account of all Mozart's compositions freed my book from all the notices and references found necessary {INTRODUCTION.} (xxvii)