Which of these celebrities was not a Hollywood film composer?

Rouben Z. Mamoulian (October 8, 1897 – December 4, 1987) was an American film and theater director. He was born in Tiflis, Russian Empire (now Tbilisi, Georgia), to a family of Armenian descent. His mother, Virginia (née Kalantarian), was a director of the Armenian theatre and his father, Zachary Mamoulian, was a bank president.

On New Year's Eve, 1920, Mamoulian arrived in London, worked with émigré actors and directed a play "The Beating on the Door" at St James's Theatre. He was then invited by Austin Page and Vladimir Rosing to co-direct. He would also direct operettas/musicals in London (1920s).

After moving to the US in 1923, he worked for the Theatre Guild and directed the play "Porgy" (1927); he later directed the original production of its musical adaptation, "Porgy and Bess" (1935). He also did other musicals such as "Oklahoma!" (1943) and "Carousel" (1945).

Invited to direct the film musical "Applause" (1929), he won acclaim for his camera work; his later films include "City Streets" (1931), "Queen Christina" (1933, Greta Garbo), "Becky Sharp" (1935), "The Gay Desperado" (1936), "Blood and Sand" (1941), and "Silk Stockings" (1957). He was noted in reviews for the skillful blending of music and sound effects with an imaginative visual rhythm.

With Max Steiner (1888 – 1971), an Austrian; Dimitri Tiomkin (1894 – 1979), a Russian/American artisan; and Alfred Newman (1900 – 1970), an American, each was a very skilled Hollywood musical director/composer.