As Hollywood transitioned from silent to sound cinema, studios grappled with how to “realistically” incorporate the film score into a movie. Should the music remain strictly diegetic, playing only when the narrative reveals the sound's source? Or would it be appropriate to incorporate nondiegetic music that only the audience can hear? Although such concerns may seem laughable to a modern audience, throughout the 1930s, Hollywood worried that nondiegetic music would pull viewers from the narrative and make them question the music's source. Recalling the early sound era in his memoir, composer Max Steiner explained:

While such tactics were not uncommon in early Hollywood pictures, the need for justification subsided and nondiegetic film scores soon became convention.

Several other industry practices also developed alongside the accepted shift to nondiegetic scoring. Largely abandoning the diegetic music of the early sound era, for example, many composers employed more music, both in terms of length and orchestral size. Additionally, several leading film composers, including Erich Korngold, Max Steiner, and Alfred Newman, often wrote in a late-Romantic compositional style. They frequently employed the soaring melodic lines; full, rich sound; use of leitmotivs; and expanded harmonic language of such art music composers as Johannes Brahms, Gustav Mahler, Richard Strauss, and Richard Wagner.

There were many reasons for employing this late-nineteenth-century sound, one of the most practical being a simple continuation of what came before it. As Mervin Cooke suggested, this practice was an extension from earlier silent film scores; it is likely that the composers continued using what they knew. Additionally, Claudia Gorbman proposed the influence of cultural musical codes on the accepted Hollywood sound, explaining that “the core musical lexicon [of film] has tended to remain conservatively rooted in Romantic tonality, since its purpose is quick and efficient signification to a mass audience.”