In songs, the expression is in an inverse ratio to the interest of the words. Good poetry is hardly susceptible of any but an uncolored music, just enough to sustain the voice; the thought, in effect, crowds out the feeling, and, a choice being forced upon the attention, too much musical accent would weaken the thought. For a full musical interpretation of the feeling, a third-rate poetry, only indicating the subject, is best, for it permits the concentration of all the attention upon the emotional expression. This is, ordinarily, the character of the librettos of operas, in which everything is subordinated to the music; but the song, the interest of which lies in the conception, is accommodated with a colorless melody.
By considering music as the language of the feelings, we are enabled to account for the power it has over masses composed of the most incongruous elements. An address can not affect alike persons of different degrees of intellectual development, and must fall without making any impression on a part of the audience. There is less difference in the capacity for feeling, and all are more or less subject to the same transports of emotion. The masses feel more than they think.
It is interesting to remark the generally simple and touching expression of popular songs. The feeling is brought out in its purity without science or preparation, and the result is a music full of artless charms, the inexhaustible source to which composers, knowing that they can not find better ones, go for the themes of their works. These popular songs are generally of a sad character, and tell of vague aspirations and indefinite desires. Thus have originated those dreamy melodies with which working-people love to lull their melancholy, and which are frequently the only source to which we can go for the history of those who have lived and suffered in obscurity.
As different human races have their several languages, so each one has its own musical system; and these various systems, the existence of which is explainable by the action of the same causes that have made different words to designate the same things, prove that the origin of the two languages is common, and that the one is the spontaneous expression of feelings, as the other is of thoughts. Like alphabets, gamuts also may differ within certain limits. They are also not fixed, and undergo the evolution common to all languages. Most uncivilized peoples are unacquainted with semitones, and use scales with full intervals. This is easily accounted for if we suppose that these intervals are the ones which represent the elementary intonations, and that they constitute a music near its origin. The need of representing shades of feeling brings about a progressive filling up of the intervals. The ancient Celts excluded semitones, while the music of the Greeks found refined expression in quarter-tones. Our musicians are also sometimes tempted to reduce our minimum interval of a semitone, and some performers abuse this process to an extravagant degree.