Never Let Me Go,” based on the Kazuo Ishiguro novel about cloned children raised specifically to provide donor organs as young adults, needed music that was as delicately balanced as the storytelling.

Says British composer Rachel Portman: “The film is ultimately very moving, extremely sad. I wanted to put some hope into it, some humanity in the music. It was important to me that there was a real emotional heartbeat in the midst of this story.”

Portman, the first woman to win a scoring Oscar (“Emma,” 1996), felt that a “huge sweeping score” would have been wrong for the film, which centers on the lives of three young people (Carey Mulligan, Keira Knightley, Andrew Garfield) who discover their fates as young teens. At most, she used 48 players.

“It’s sort of a chamber piece,” she says, noting that most of the score was written for piano, strings and harp, with solos for violin and cello. “If you use a solo instrument, it’s like having a voice,” she says. “It highlights the emotion.” But, she adds, “the violin is played with virtually no vibrato, because I didn’t ever want it to sound sentimental.”

Portman, who has two other previous Oscar noms (“The Cider House Rules,” “Chocolat”), spent four months on the film. At the behest of director Mark Romanek and the producers, she experimented with other approaches, including the use of child’s voice and a big finale cue. But in the end, they opted for a simpler, more subtle approach.

“I know, from looking at a scene, how much emotion to give a piece of music to play against it,” she says. “For my own taste, I stay on the side of restraint, because I think it works better in film.”

Get more from Eye on the Oscars: Music:
Music branch can’t please all the people | Song category hangs by thread | Daft Punk immersed in ‘Tron’ | Songs in contention
Michael Brook | Carter Burwell | Danny Elfman | Grizzly Bear | Jan Kaczmarek | Rachel Portman | Anton Sanko