It is not amiss to compare El Greco to some great composer whose medium is his orchestra. The latter is made up of units, but there is no established proportion of the relation which they bear to each other and to the whole. It is a flexible instrument in which the composer makes his own adjustments. If for the interpretation of his theme he exaggerates the wind instruments or chooses to introduce new devices for attaining an effect, he is judged solely by the harmonious result. For music being a completely abstract art, the verdict depends upon the structure, scope and quality of its expression. The art of painting is less abstract, being limited by the sense appreciation of the eye and the need of attaching the expression to some visible object; but, as far as possible with the liberty of the musical composer, El Greco composed his symphonies of form and color. * * * * * This liberty of composition was only gradually evolved. His earlier work, executed during his first years in Toledo, exhibit traces of his Venetian training. _The Assumption of the Virgin_, which is now owned by the Art Institute of Chicago, is in its treatment of the forms and composition still Titianesque; but already the influence of the new environment upon El Greco’s individuality is apparent. He has caught as yet little if any of the mystic fervor, but the types, particularly of the apostles, are local; the draperies are handled broadly and plastically, and the color is no longer of Venetian sumptuousness. The process of dematerialization has begun, which will be carried on until in the great works of the artist’s maturity the Venetian richness of pigment, full of mundane splendor, has entirely disappeared in cool, austere harmonies of blue, lemon and yellow, black, grey, white, olive green and silvery carnation. Touches of warm color occur but they are comparatively rare. Least of all in the great altarpiece does El Greco use color for effects of pageantry or mere decoration. His use is interpretative of spiritual significance. In his portraits it is psychologically expressive.