 To compose the score, Selznick chose Max Steiner, with whom he had worked at RKO Pictures in the early 1930s.Warner Bros.—who had contracted Steiner in 1936—agreed to lend him to Selznick.Steiner spent twelve weeks working on the score, the longest period that he had ever spent writing one, and at two hours and thirty-six minutes long it was also the longest that he had ever written.