Aaron Copland's music for The Red Pony (1948-49), based on John Steinbeck's story collection, is probably the best known of his film scores. The effectiveness of The Red Pony score stems from Copland's belief that film music should be subordinate to the film it accompanies. Copland composed The Red Pony score using his self-described method of "assembly," augmenting this process with devices to synchronize the music with the picture. Examination of archival sources shows how the score reflects the acknowledged influence of Igor Stravinsky, the needs of the film medium, and the plot of The Red Pony specifically. Despite Copland's modern style characteristics, the music functions much like a conventional Hollywood film score.