The fundamental question at issue is this――is a work of art a complete and finite thing, beautiful when it left its maker’s hand, beautiful now and for ever, or is it frankly transitory, a momentary expression of a momentary experience, speaking as a rule only to those who belong to the same generation? The art dealer and the museum director naturally take the first view. If you have paid some huge sum for a picture, you may hesitate to burn it as soon as you are tired of it. You must at least go on pretending to admire it. And since material works of art are always before us, it is natural that philosophers should have started to construct their artistic theories from an architectural or pictorial point of view. It is perhaps inevitable that the criticism of music should borrow phrases from that of the plastic arts, because music is an art so entirely complete in itself that it has never yet evolved an adequate vocabulary of technical terms, let alone a vocabulary in which its nature can be described to the non-technical reader. But although there may be something to be said for Goethe’s famous comparison of architecture to “frozen music,” it is with poetry rather than with the plastic arts that music more legitimately may seek affinity. Literary critics have never yet succeeded in defining what poetry is; but we can at any rate say that what distinguishes poetry from a statement of the same idea in prose is chiefly the presence of qualities which are common both to poetry and to music. It has been clearly shown, for instance, that the lyric poetry of classical Greece employed devices of construction which are curiously similar to those of Beethoven. Habit induces us to imagine that the value of Beethoven’s music depends on our conventional scale and the harmonies derived from it; but though we are bound to admit that every artist is limited by the peculiar qualities of his materials, whether they be words, marble or musical sounds, we know that they cannot be turned to artistic account unless he has chosen them, imperfect as they are, to serve him in the expression of something conceived in his imagination――something of which he himself is definitely aware although he cannot communicate it to others without this material presentation. That which is common to poetry and music is not a metaphysical figment. It may often elude analysis; but at present it has hardly been investigated scientifically. It ought to be possible to find out a great deal more about it, and to find out a great deal more about what constitutes the “poetical” quality――to use the epithet in a familiar if not very accurate sense――of musical interpretation, for these things are problems of actual physical sound.