File Photo: Composer Howard Shore, taken on March 2017 in Berlin. AP
"I like to improvise," Shore told AFP. "I like to read the novel, the play or the script and then I dream and go into a state of improvisational association with the world of the film.
"That's where the music comes from, from dreaming the story," he said.
Shore, 76, was present at the Cannes Film Festival on Monday as part of the annual celebration of composers.
Sacem, France's songwriters' association, are calling for Cannes to "give music its rightful place" and hand out an award for a movie's score.
Under French and US law, composers are officially "co-authors" of every film alongside the director and screenwriter, Cecile Rap-Veber, Sacem's CEO told AFP.
"It's clear, with very few exceptions, that if you take the music out of a film you'll quickly see something is missing," she said.
"It's one of the indispensable elements that generate emotions and carry the message of the story," she added.
Shore welcomes any effort to recognise the work of film composers, who he says play a crucial role in "maintaining the relationship between the audience and storytelling".
He won three Oscars for his work with Peter Jackson on the "Lord of the Rings" and "The Hobbit" trilogies.
"Peter was in the studio every day. He was a great collaborator," Shore recalled.
He has also worked regularly with Martin Scorsese (including on "The Departed" and "The Aviator") and other Hollywood greats such as David Fincher (for "Seven" and "The Game").
But his longest relationship has been with Canadian director David Cronenberg, from early films like "The Fly" and "Videodrome" to last year's body-horror "Crimes of the Future" and his upcoming semi-autobiographical film, "The Shrouds".
"David and I are almost like brothers, we grew up in the same neighbourhood," said Shore.
"He's very instinctive, never looking back. In the 16 films we've done together, we've tried many different things."
Shore began his career as a jazz musician and later worked on the early anarchic episodes of TV show "Saturday Night Live".
What drew him to film work was the chance to mess around with technology -- "all the microphones and acoustics".
"I started in the theatre. It was a great training ground," he said.
"But since then, I have tried pretty much everything you can try in terms of using music."