After the introduction of the principle of tonality music developed with remarkable rapidity. In one hundred and fifty years it made more progress toward an ideal beauty and as a means of emotional expression than it had made in the thousands of years that had passed since the first note was sung. For by this principle of tonality, melody and harmony as we know them became possible. All that went before was either the vague, formless, unsymmetrical production of popular mood and fancy, or the dry formula-work of musical pedants. And yet within a century we have such a result as Stradella's divine _Aria di chiesa Se i miei sospiri_, which, whether for its melody, its harmony, or its emotional expression, intense yet kept within the bounds of a lofty and almost serene dignity, is unsurpassed by any vocal work which has been since produced. It has been said by some that this air was not written by Stradella. M. Fetis, however, does not doubt it; and the result of the discussion is that it is assigned to the great Italian singer. The story of his having saved his life by singing it--two assassins who followed him into a cathedral to put him to death for having robbed a nobleman of his beautiful mistress having been disarmed and sent off repentant by the charm of his voice and of the music--is probably known to many of my readers. Did any of them ever hear in a composition by Wagner or Liszt, or any of that crew, a melody of which it could be believed or for a moment supposed that it would produce such an effect, even if it were sung by a seraph?