Why is it that most persons are more interested in vocal than in instrumental music? Obviously because, as Richard Wagner remarks, "the human voice is the oldest, the most genuine, and the most beautiful organ of music--the organ to which alone our music owes its existence." And not only is the sound or quality of the human voice more beautiful than that of any artificial instrument, but it is capable of greater variation. Although a good artist can produce various shades of tone on his instrument, yet every instrument has a well-defined characteristic _timbre_, which justifies us in speaking, for instance, of the majestic, solemn trombone, the serene flute, the amorous violoncello, the lugubrious bassoon, and so on. The human voice, on the other hand, is much less limited in its powers of tonal and emotional coloring. It is not dependent for its resonance on a rigid tube, like the flute, or an unchangeable sounding-board, like the violin or the piano, but on the cavity of the mouth, which can be enlarged and altered at will by the movements of the lower jaw, and the soft parts--the tongue and the glottis. These movements change the overtones, of which the vowels are made up, and hence it is that the human voice is capable of an infinite variety of tone-color, compared with which Wagner admits that even "the most manifold imaginable mixture of orchestral colors must appear insignificant." Notwithstanding that the superiority of the voice is thus conceded, even by the greatest magician of the orchestra, we daily hear the complaint that the good old times of artistic singing are gone by, and have been superseded by an instrumental era, in which the voice merely plays the part of the second fiddle and is maltreated by composers, who do not understand its real nature. So far is this opinion from the truth that it must be said, contrariwise, that it is only within the last century--I might almost say the last half century--that composers have begun fully to recognize the true function of the human voice and its principal advantage over instruments. What is this advantage? It is the power of articulating, of uniting poetry with music, _definite words with indefinite tones_. Every instrument, as I have just said, has a characteristic emotional tone-color. But the emotions expressed by them are vague and indefinite. A piece of instrumental music can express an eager, passionate yearning for something, but it cannot tell what that something is--whether it is the ardent longing of an absent lover, or the heavenward aspiration of a religious enthusiast. The vocalist, on the other hand, can clearly tell us the object of that longing by using definite words. And by thus arousing reminiscences in the hearer's mind, and adding the charm of poetry to that of music, he doubles the power and impressiveness of his art.