Yet even in Italy in the Renascence the most popular form of the drama, the improvised play which we call the comedy-of-masks, was performed in a traditional stage-setting representing an open square, whereon only the back-cloth seems to have been the work of the scene-painter, the sides of the stage being occupied by four or more houses, two or three on each side, often consisting of little more than a practicable door with a practicable window over it, not made of canvas, but constructed out of wood by the carpenter, with the solidity demanded by the climbing feats of the athletic comedians and by their acrobatic agility. The traditional set of the comedy-of-masks conformed to that recommended for the comic drama by Serlio, in his treatise on architecture, published in 1545; but it may be noted also that Serlio's suggested set for the tragic drama was not dissimilar even if it were distinctly more dignified. III The opera seems to have been the direct descendant of the court-ballet, known in England as the mask, as that in its turn was derived from the open-air spectacle of the Italian Renascence, such as survived in Florence in the seventeenth century. In the beginning the court-ballets of France, like the masks of England, were not given in a theater with a stage shut off by a proscenium arch, but in the ball-room or banqueting-hall of a palace. One end of this spacious apartment, often but not always provided with a raised platform, served as the stage whereon one or more places, a mountain, for instance, and a grotto, were represented, at first by the decorated machines of the artistic engineers only, but afterward by the canvas frames of scene-painters. The action of the court-ballets or of the masks was not necessarily confined to this stage, so to call it. The spectators were ranged along the walls and under the galleries (if there were any), leaving the main part of the hall bare; and the performers descended frequently into this area, which was kept free for them, and which was better fitted for their dances and processions and other intricate evolutions than the scant and cluttered stage.