Early television change
In live theatre the difference between comedy and tragedy became less and less significant, in mass media, comedy and drama were clearly separated. Comedies, especially, were meant to only have jokes and not any serious content.
By the early 1960s, television had started to present half-hour long "comedy" series, or one hour long "dramas." Half-hour series were mostly situation comedy or family comedy. One hour dramas could have detective series, westerns and science fiction.
Recent drama-comedy on television change
A drama-comedy today is usually an hour-long dramatic series with funny jokes such as Moonlighting, Northern Exposure, Auf Wiedersehen, Pet, Buffy the Vampire Slayer, Eureka, Life on Mars, House, Desperate Housewives, Charmed, Popular, Skins, Monk, Psych, Gilmore Girls, The O.C., Studio 60 on the Sunset Strip, Ally McBeal, Ugly Betty, Brothers & Sisters, Grey's Anatomy or Boston Legal".