Link suggested by Mark EvanierFrom Wikipedia...The Playhouse is a 1921 film written and directed by and starring Buster Keaton. The movie runs for 22 minutes, and is most famous for its opening sequence in which Keaton plays every role.
The film is set up as a series of humorous tricks on the audience, with constant doubling, and in which things are rarely what they at first seem to be. It opens with Keaton attending a variety show. In this first sequence, Keaton plays the conductor of the orchestra, every member of the orchestra, the actors, the dancers, the stagehands, the minstrels, and every member of the audience, male and female. This elaborate trick-photography sequence turns out to be a dream when Joe Roberts rouses Keaton from bed. The bedroom then turns out to be not a bedroom, but a set on a stage.
Keaton's portrayal of nine members of a minstrel show required the use of a special camera shutter. It had nine exactingly-machined strips of metal which could be moved up and down independently of each other. Elgin Lessley, Keaton's cameraman, shot the far-left Keaton with the first shutter up, and the others down. He then rewound the film, opened the second segment, and re-filmed the next Keaton in sequence. This continued for each of the remaining seven Keatons. The camera was hand-wound, so the Lessley's hand had to be absolutely steady, with no variation in its speed. Keaton had to move meticulously in each of his appearances, so he relied on a metronome to guide him, not a problem in a silent film. It was decades before Keaton, who masterminded this, revealed his technique to other filmmakers.
The second half of the film features Keaton's character pursuing a girl who happens to be a twin, and he can't remember which he has fallen for. The film also stars, uncredited, Virginia Fox as one of the twins and Joe Roberts as another actor and stage manager. Edward F. Cline co-wrote the production and appears, uncredited, as a monkey trainer, whose monkey Keaton impersonates after accidentally letting him escape. The impersonation is stunning in Keaton's movements and expressions. The facial markings contribute to the illusion, but it is his adopting of the mannerisms that give the scene its full impact.
The most famous quote from the film is that of an audience member in the first part, played by Keaton. When he reads the playbill listing Keaton in every role in the play, he remarks to his wife, also played by Keaton, "This fellow Keaton seems to be the whole show." This was a gibe at one of Keaton's contemporaries, Thomas Ince, who credited himself generously in his film productions.
In interviews with Kevin Brownlow (published in the latter's excellent study of silent films, The Parade's Gone By, 1968, pp. 491-492), Keaton claims he gave the director's credit to Cline mainly because he didn't want to appear too Ince-like, himself! "Having kidded things like that, I hesitated to put my own name on as a director and writer."