The great edifice of art, in fact, is like those Gothic cathedrals on which generations of men successively labored; thousands of common workmen hewed their foundation stones; finer minds, architects, smiths, brass founders, glass makers and sculptors, wrought and decorated the superstructures; and the work of each, whatever his personal skill and devotion, was valuable only because it built upon and added to that of all the rest. The soaring spires are firmly based on blocks of stone ploddingly adjusted; the windows, often of such a perfect beauty that they seem created rather than constructed, had nevertheless to be built up bit by bit; and all the marvelous organism of pillars, arches and buttresses is so delicately solid, so precariously stable, that had one stress been miscalculated, one joint inaccurately made, the whole would collapse. So it is with the edifice of art, and particularly with that of music, which depends for its very material on the labors of musicians. Pigments, clay, marble, the materials of the plastic arts, exist already in the world; but the whole ladder of fixed tones on which music is built is the product of man's æsthetic sense, and had to be created slowly and laboriously by many generations of men. The successions of chords which every banjo player strums in his accompaniments were the subject of long trial by the mediæval composers. The hymn tune that any boy can write is modeled on a symmetrical scheme of phrases developed by countless experimenters. It took men centuries to select and arrange the eight tones of the ordinary scale, and centuries more to learn how to combine them in chords. And the most eloquent modern works depend on this long evolution of resources just as inevitably as the Gothic spire rests on the hewn stones so carefully laid. In the art, as in the cathedral, the seen rests upon the unseen, the beautiful upon the solid, the complex upon the simple, the new upon the old. The product of a thousand artists, music is as dependent on each as the coral reef on the tiny indispensable body of each insect; and on the other hand the individual musician, whatever his ability, is great only as he uses the equipment his fellows have prepared--«the greatest is the most indebted man.»