Every form of art has a variety of sides and aspects which appeal to different men in different degrees. A work may entrance one man through the beauty of its colour, while another finds it insupportable for its weakness of design. One man cares only for melody, when another is satisfied with grand harmony; one wants artistic skill, when another cares only for expression. This is true even of symphonies and sonatas, and such pure examples of human artistic contrivance; but in opera the complication and variety of constituent means of effect intensify the difficulties of the situation tenfold, and the chances of satisfying all tastes are necessarily extremely remote, for the elements that have to be combined seem to be almost incompatible. Scenic effect has to be considered as well as the development of the dramatic situations, and the dialogue, and the music. The action and the scenery distract the attention from the music, and the dialogue naturally goes too fast for it. Music, being mainly the expression of states of mind and feeling, takes time to convey its meaning; and in all but the most advanced stages of art the types of design which seem indispensable to make it intelligible require the repetition of definite passages of melody, and submission to rules of procedure which seem to be completely at variance with dramatic effect.