Adolphe Appia (ädôlf´ äp´pyä), 1862–1928, Swiss theorist of modern stage lighting and décor. In interpreting Wagner's ideas in scenic designs for his operas, Appia rejected painted scenery for the three-dimensional set; he felt that shade was as necessary as light to link the actor to this setting in time and space. His use of light, through intensity, color, and mobility, to set the atmosphere and mood of a play created a new perspective in scene design and stage lighting.
See his Work of Living Art and Man Is the Measure of All Things, in a single volume, ed. by B. Hewitt (tr. 1960); R. C. Beacham, Adolphe Appia: Theatre Artist (1987).