Speaking to an enthusiastic audience at the Museum of Modern Art on January 10, 1940, Copland shared his thoughts on music's role in film. He had just returned to New York after composing the score for Lewis Milestone's Of Mice and Men (1939), and he spoke candidly to the crowd:

It is noteworthy that Copland, well trained in the art music tradition, could also now speak knowledgeably about the world of film composition. Few composers during this time had an intimate understanding of both fields, making Copland's experiences and theories quite valuable as one investigates the development of film music throughout the 1940s. What's more, due to his stature in the art music space, Copland's fresh theories on film music held a significant amount of weight, which potentially granted him greater influence in the industry than his contemporaries.

Offering his first piece of advice regarding “the proper function for film music,” Copland explained, “Film music only makes sense if it helps the picture. In other words, film music is not concert music, and listening to film music is not like listening to a concert.” Although this was a guideline in which he believed, as a concert hall composer first, he occasionally struggled with balancing the prominence of music in a film. In fact, in a 1940 New York Times article, Copland openly objected to the argument that a film score should be judged by its invisibility, saying, “I cannot bring myself to believe that the moment one becomes aware of the ‘background music’ in a motion picture it has automatically ceased to fulfill its function.”