Abstract: In teaching harmony, I have again and again been struck with the very inadequate attention given in most text-books to its tonal aspect—that is, to the relation of notes and chords, especially dissonances, to the tonic or key-note as well as one to another. It is with the view of emphasizing this aspect of the subject that the following notes have been written. Whether or not I have over-estimated its importance, I must leave it to my audience to decide; but at least it must be conceded that to study harmony without giving any attention to the question of tonality would be absurd—nay, would not be to study harmony at all.