 Michael Giacchino composed the film 's score ; this was his fifth collaboration with Pixar and his second collaboration with Docter after Up . The producers first met with Giacchino to explain the film 's concept and screen it for him . In response , he composed an eight @-@ minute suite of music , unconnected to the film , based on his emotions viewing it . Rivera noted that while both Giacchino and Docter were musicians , they discussed the film in terms of story and character . 
