It's well-known that the late composer Henry Brant had an active parallel career as on orchestrator and composer for film, but a lot of his work took place under- or uncredited, which is standard practice in film music. During his life, Brant was always modest about his work as an orchestrator for the scores of colleagues, characterizing it as always implementing the style and preferences of the composer rather than in his own. Mr Brant's musical executor, Kathy Wilkowski, has been kind enough to share the following list of films on which he worked.
First, his collaborations as orchestrator:
for Virgil Thomson: The River (1937), The Plow That Broke the Plains (1936), Louisiana Story (1948; the score won Thomson the Pulitzer Prize in Music, Brant was credited as "music technical assistant".)
for Aaron Copland: The City (1939)
for George Antheil: The Scoundrel (1935)
for Marc Blitzstein: at least two films.
for Douglas Moore: Power on the Land (1940) , Youth Gets a Break (a WPA-related film; Brant stated: "it was for full orchestra; he left it to me."
for Alex North: The Misfits (1961), Cleopatra (1963), Cheyenne Autumn (1964), Who's Afraid of Virginia Wolff (1966), Africa (ABC-TV documentary, 1967), 2001: A Space Odyssey (the score was not used in the released film), The Devil's Brigade (1968), Carny (1980; includes two compositions by Brant which were organ solos extracted from Brant's 1956 opera The Grand Universal Circus), Dragonslayer (1981), Good Morning Vietnam (1987)
for Gordon Parks: The Learning Tree (1970)
Brant's own work as a film composer was also extensive, particularly for documentary and independent films. It includes: Playing Fields of America (aka Sport Film) (1943), Capitol Story (aka Public Health, for the OWI)(1944), the Pale Horseman (OWI)(1944), Journey into Medicine (1946), Osmosis (1946), Outbreak (1947), The Big Break (1951), Ode to a Grecian Urn (1953; an avant-garde film to which Brant improvised on dulcimer, double-flageolet, ox-bells, double-ocarina, celesta, bass recorder, and Persian oboe), The Secret Thief (1956), Your Community (1956), Dr. "B" (1957), Endowing our Future (1958), Fibres in Civilization (1958), Peace Music for U.N. Day (1959), a “Wind quintet film” (1960), Early Birds (1961), Fertility & the Physician (1965), Jack Levine (1966), Chartres Cathedral (1970), Marcel Duchamp (1978; improvised by Brant), The Trappers (1981), and Noch Ist Polen Nicht Verloren (1991)