An anthology film or omnibus film or portmanteau film is a film consisting of several different short films, often tied together by only a single theme, premise, or brief interlocking event (often a turning point). Sometimes each one is directed by a different director. Sometimes there is a theme, such as a place (e.g. New York Stories), a person (e.g. Four Rooms), or a thing (e.g. Twenty Bucks, Coffee and Cigarettes), that is present in each story and serves to bind them together. One of the earliest films to use the form was the 1948 film Quartet based on stories by W. Somerset Maugham. This led to two sequels, Trio and Encore (1951), as well as imitators like O. Henry's Full House.
Sometimes there is one "top-level" story, a framing device, which leads into the various "sub-stories", as in Tales of Manhattan, Flesh and Fantasy (1943), Dead of Night and The Illustrated Man. The former helped to popularise the format for horror films (though they had existed as far back as Unheimliche Geschichten (1919)), and British company Amicus made several such films in the 1960s and 1970s. Another variation is when different sub-narratives share a common incident (usually a turning point), as in Amores perros.
The Red Violin (1998) could also be considered a portmanteau film, since the storylines revolve around the various owners of a precious sixteenth-century violin through the centuries. Similarly, 1964's The Yellow Rolls-Royce follows the owners of the titular vehicle.
Gene Kelly's 1956 all-dance film Invitation to the Dance consisted of three distinct stories, each different in tone and with its own plot line. Kelly appeared in each of the stories.