Billy Bob Thornton suffers from "pretty serious" Obsessive Compulsive Disorder (OCD).
The actor, who is promoting his latest project - a TV adaptation of 1996 Oscar-nominated movie Fargo - revealed he is obsessive over music and uses songs to help him get into character for his roles.
In the 10-part series, Thornton portrays manipulative criminal Lorne Malvo, who meets a naive insurance salesman and brings out his dark side.
"Every day in my dressing room I listened to Pet Sounds by The Beach Boys," the star has told the New York Daily News. "I'm always thinking about music. I also have pretty serious OCD, so that contributes."
Music was also part of Thornton's 1996 breakthrough film Sling Blade, which he wrote, directed and starred in.
"I wrote Sling Blade, every word of it, while I was listening to a loop of Holiday In Berlin, by the Mothers of Invention," Thornton said.
The 58-year-old sees himself taking on more TV projects in the future, saying he prefers to play interesting, multifaceted characters on the small screen rather than one-dimensional leading men in cinema blockbusters.
"Television today is doing those mid-level, character-based stories the movies used to do," Thornton said. "I'm not blaming Hollywood. They're just responding to who goes to the movies, which is 19-year-olds.
"But for the kind of thing I like to do, the place to look now is television."
