So large a number of works on Harmony already exists that the publication of a new treatise on the subject seems to call for explanation, if not for apology. The present volume is the outcome of many years experience in teaching the theory of music, and the author hopes that it contains sufficient novelty both in plan and in matter to plead a justification for its appearance.<br><br>Most intelligent students of harmony have at times been perplexed by their inability to reconcile passages they have found in the works of the great masters with the rules given in the textbooks. If they ask the help of their teacher in their difficulty, they are probably told, "Bach is wrong," or "Beethoven is wrong," or, at best, "This is a licence." No doubt examples of very free part-writing may be found in the works of Bach and Beethoven, or even of Haydn and Mozart; several such are noted and explained in the present work. But the principle must surely be wrong which places the rules of an early stage of musical development above the inspirations of genius! Haydn, when asked according to what rule he had introduced a certain harmony, replied that the rules were all his very obedient humble servants; and when we find that in our own time Wagner, or Brahms, or Dvorak breaks some rule given in old text-books there is, to say the least, a very strong presumption, not that the composer is wrong, but that the rule needs modifying. In other words, practice must precede theory. The inspired composer goes first, and invents new effects; it is the business of the theorist not to cavil at every novelty, but to follow modestly behind, and make his rules conform to the practice of the master. It is a significant fact that, even in the most recent developments of the art, nothing has yet been written by any composer of eminence which a sound theoretical system cannot satisfactorily account for; and the objections made by musicians of the old school to the novel harmonic progressions of Wagner are little more than repetitions of the severe criticisms which in the early years of the present century were launched at the works of Beethoven.