It is the second collaboration between Michael Giacchino and Pete Docter, after previously working on Up, which received an Academy Award for Best Original Score.

The score was recorded between January and May 2015, and featured more orchestral and symphonic music accompanied by a range of instruments, from piano, guitar, drum, organ and harp.

Rivera remarked that as both Giacchino and Docter were musicians, and they discussed the film in terms of story and character.

[9] In accordance with its creative preference, a progressive soundscape was made by sound designer Ren Klyce, who was joined by Rivera.

[12][13] While in the music session, Docter felt its score "bittersweet" and "nostalgic" after he "grew up playing the violin and bass".

[15] In a press release by Walt Disney Records, excerpts from Giacchino stated that "Pete [Docter] wanted the music to feel as if it was coming from the inside—from internal thoughts".