The paper analyses contributions of Otakar Zich, Czech aesthetician and theatrologist, to the theory of drama and opera acting. Zich's starting point was aesthetic structuralism. In his systematic work The Aesthetics of Dramatic Art (Prague 1931), he presents his view on opera acting. It is based on an analysis of performing arts that distinguishes a dramatic character and a performer. Zich believes that opera composer does not compose just the dramatic text, but creates both musical and dramatic situations. From this position further requirements for artistic work of opera actor are derived, especially the ways of responding to opera music.