We see, then, that emotion may be expressed by sound and be awakened by sound, and this obtains among human beings no less than among the lower animals. In the long process of ages sound qualities have become indissolubly associated with emotional states, and have become the most exciting, the most powerful sense stimulus in producing emotional reactions. The cry of one human being in pain will excite painful emotions in another. An exclamation of joy will excite a similar emotion in others, and so on through the whole range of human emotions.

Herbert Spencer holds that the beginning of music may be traced back to the cry of animals, which evidently has an emotional origin and purpose. It is a far cry from the beginning of music as described by Spencer to the modern art song, but from that time to this the principle has remained the same. The emotional range of the lower animals is small, doubtless limited to the expression of bodily conditions, but the human race through long ages of growth has developed an almost unlimited emotional range, hence the vehicle for its expression has of necessity increased in complexity.

To meet this demand music as a science has evolved a tone system. That is, from the infinite number of tones it has selected something over a hundred having definite mathematical relationships, fixed vibrational ratios. The art of music takes this system of tones and by means of combinations, progressions and movements which constitute what is called musical composition, it undertakes to excite a wide variety of emotions.

The aim and office of music is to create moods. It does not arrive at definite expression. There is no musical progression which is universally understood as an invitation to one’s neighbor to pass the bread. The pianist cannot by any particular tone combination make his audience understand that his left shoe pinches, but he can make them smile or look serious. He can fill them with courage or bring them to tears without saying a word. In listening to the Bach B Minor Mass one can tell the Sanctus from the Gloria in Excelsis without knowing a word of Latin. The music conveys the mood unmistakably.

A song is a union of music and poetry, a wedding if you please and as in all matrimonial alliances the two contracting parties should be in harmony. The poem creates a mood not alone by what it expresses directly but by what it implies, what it suggests. Its office is to stimulate the imagination rather than to inform by direct statement of facts. The office of music is to strengthen, accentuate, and supplement the mood of the poem, to translate the poem into music. The best song then, will be one in which both words and music most perfectly create the same mood.

Arnold Bennett’s definition of literature applies equally well to the song. He says: “That evening when you went for a walk with your faithful friend, the friend from whom you hid nothing—or almost nothing—you were, in truth, somewhat inclined to hide from him the particular matter which monopolized your mind that evening, but somehow you contrived to get on to it, drawn by an overpowering fascination. And as your faithful friend was sympathetic and discreet, and flattered you by a respectful curiosity, you proceeded further and further into the said matter, growing more and more confidential, until at last you cried out in a terrific whisper: ‘My boy she is simply miraculous:’ At that moment you were in the domain of literature.” Now when such impassioned, spontaneous utterance is brought under the operation of musical law we have a perfect song. The composer furnished the words and music, but the thing which makes it a song comes from the singer, from the earnestness and conviction with which he delivers the message.

Songs are divided into two general classes: those expressing the relationships of human beings, such as love, joy, sorrow, chivalry, patriotism, etc., and those expressing the relationship of man to his creator; veneration, devotion, praise, etc. The two great sources of inspiration to song writers have always been love and religion.

What are the principles of song construction? They are all comprised in the law of fitness. The composer must do what he sets out to do. The materials with which he has to work are rhythm, melody and harmony. The most important thing in a song is the melody. This determines to a very great extent the health and longevity of the song. Most of the songs that have passed the century mark and still live do so by reason of their melody. There must be a sense of fitness between the poem and the melody. A poem which expresses a simple sentiment requires a simple melody. A simple story should be told simply. If the poem is sad, joyous, or tragic the melody must correspond. Otherwise the family discords begin at once. Poetry cannot adapt itself to music, because its mood is already established. It is the business of the composer to create music which will supplement the poem. A lullaby should not have a martial melody, neither should an exhortation to lofty patriotism be given a melody which induces somnolence.

The same sense of fitness must obtain in the accompaniment. The office of the accompaniment is not merely to keep the singer on the pitch. It must help to tell the story by strengthening the mood of the poem. It must not be trivial or insincere, neither must it overwhelm and thus draw the attention of the listeners to itself and away from the singer.

The accompaniment is the clothing, or dress, of the melody. Melodies, like people, should be well dressed but not over dressed. Some melodies, like some people, look better in plain clothes than in a fancy costume. Other melodies appear to advantage in a rich costume. Modern songwriters are much inclined to overdress their melodies to the extent that the accompaniment forces itself upon the attention to the exclusion of the melody. Such writing is as incongruous as putting on a dress suit to go to a fire.