<P> When Kathryn Trosper Popper died on March 6, 2016, at the age of 100 she was reported to be the last surviving actor to appear in Citizen Kane . Jean Forward, a soprano who dubbed the singing voice of Susan Alexander, was the last surviving performer from the film before her death in 2016 . Warrick was the last surviving member of the principal cast at the time of her death in 2005 . Sonny Bupp, who played Kane's young son, was the last surviving credited cast member of Citizen Kane when he died in 2007 . </P> <P> Production advisor Miriam Geiger quickly compiled a handmade film textbook for Welles, a practical reference book of film techniques that he studied carefully . He then taught himself filmmaking by matching its visual vocabulary to The Cabinet of Dr. Caligari, which he ordered from the Museum of Modern Art, and films by Frank Capra, René Clair, Fritz Lang, King Vidor and Jean Renoir . The one film he genuinely studied was John Ford's Stagecoach, which he watched 40 times . "As it turned out, the first day I ever walked onto a set was my first day as a director," Welles said . "I'd learned whatever I knew in the projection room--from Ford . After dinner every night for about a month, I'd run Stagecoach, often with some different technician or department head from the studio, and ask questions .' How was this done?' ' Why was this done?' It was like going to school ." </P> <P> Welles's cinematographer for the film was Gregg Toland, described by Welles as "just then, the number - one cameraman in the world ." To Welles's astonishment, Toland visited him at his office and said, "I want you to use me on your picture ." He had seen some of the Mercury stage productions (including Caesar) and said he wanted to work with someone who had never made a movie . RKO hired Toland on loan from Samuel Goldwyn Productions in the first week of June 1940 . </P> <P> "And he never tried to impress us that he was doing any miracles," Welles recalled . "I was calling for things only a beginner would have been ignorant enough to think anybody could ever do, and there he was, doing them ." Toland later explained that he wanted to work with Welles because he anticipated the first - time director's inexperience and reputation for audacious experimentation in the theater would allow the cinematographer to try new and innovative camera techniques that typical Hollywood films would never have allowed him to do . Unaware of filmmaking protocol, Welles adjusted the lights on set as he was accustomed to doing in the theater; Toland quietly re-balanced them, and was angry when one of the crew informed Welles that he was infringing on Toland's responsibilities . During the first few weeks of June, Welles had lengthy discussions about the film with Toland and art director Perry Ferguson in the morning, and in the afternoon and evening he worked with actors and revised the script . </P>

What was unusual about the sound production of citizen kane