Set-design, mechanical stage-sets, costumes, sound and lighting all created the illusion of magic, providing entertainment and the opportunity to stage propaganda. Classical set-design was based on the Vitruvian system of genres: palace scenery for tragedy; a city view, streets or other venues for comedy; a bosco (a scene in the woods) and a landscape for pastoral or satiric plays. However, although theatre buildings were adapted for the new challenges posed by modern set-design or innovative theatrical machinery, both court and civil theatres did have more or less the same stylistic sections: stage (stage-sets, machinery); proscenium arch (if at all, separating the audience from the stage); and seating arrangements (U-shaped, horseshoe or oval) for the audience (parterre). This comprised rows of boxes (for the noble owner of a court theatre with a magnificent balcony), and a gallery (in public theatres, tiers of seats were for all social classes: high society was seated in the lower-gallery boxes; the upper- and upper-middle classes were in the galleries above and the lower classes were in the pit.