Desplat, who thought the film as a "masterpiece", complimenting del Toro's filmmaking, said that "when the movie's that beautiful, it makes your life much easier.

Desplat won the Academy Award for Best Original Score for his work in the film,[3] his second win after The Grand Budapest Hotel.

Both the director and composer, initially wanted to collaborate on the "darker adaptation" of the 1883 Italian novel The Adventures of Pinocchio by Carlo Collodi, being planned as a stop-motion animated film, with American musician Nick Cave confirming Desplat's inclusion in the project.

In January 2017, Desplat was shown a rough cut of the finished film, and finding it similar to a musical, he agreed to compose a score.

The two melodies, one titled "Elisa's Theme", are heard at the beginning of the film and later merge into a single piece of music by the end of it.

To emphasize this effect and its final result, Desplat changed the sounds of the accompanying flutes, accordions, and whistles to "something blurred".

"[12] Filmtracks.com wrote "Desplat's music will delight his ardent enthusiasts with its intelligence, but others will remain unconvinced by his questionable choices when confronted by what they may perceive as oddly disconnected precision.

"[13] Marcy Donelson of AllMusic praised the instrumentation and his efforts in creating the "sound of water", while also adding that "Whether intentional or by unconscious influence, one may hear references to film composers from the era of the story's setting as well, including [Henry] Mancini and [Bernard] Herrmann.

"[14] All tracks are written by Desplat, except where noted As with all award seasons, a For Your Consideration album was released by Fox Searchlight Pictures in late-2017.