The advent of radio drama, cinema, and in particular television created greater pressure in marketing to clearly define a product as either comedy or drama. While in live theatre the difference became less and less significant, in mass media comedy and drama were clearly divided. Comedies were expected to keep a consistently light tone and not challenge the viewer by introducing more serious content.
By the early 1960s, television companies commonly presented half-hour-long "comedy" series or hour-long "dramas". Half-hour series were mostly restricted to situation comedy (sitcoms) or family comedy and were usually aired with either a live or overdubbed laugh track. One-hour dramas included such shows as police and detective series, westerns, science fiction, and serialized prime time soap operas.