Their scores can be huge

Creating music for games is a unique task. Since Resistance: Retribution is still being created, Schyman has to compose without seeing any of the action. He works from a spreadsheet sent by the game's developers in Oregon, with each of roughly three dozen lines telling him what kind of short song is required for a given scene. The game's programmers will later be able to take apart the 63 minutes of music clips Schyman is creating, then weave them back together in numerous combinations to make them last through hours of game play without getting tedious.

Unlike the linear storytelling of movies, the plots of games vary based on the second-by-second decisions made by players.

"With a film, you're given a scene, and you have to follow the tempo and flow that the director has created," Jablonsky said. "With games, I'm told to write a 2-minute piece of music in a certain style to make players feel a certain way. I'm not given any pictures to work from, so I have to make that up in my head. It's an interesting challenge to write without any pictures, but fun."

Brian Schmidt, a game composer in Bellevue, Wash., sums up the task by referencing a situation in the movie "The Truman Show." In it, Jim Carrey plays an insurance salesman who discovers that his entire life is a televised reality series. Since his actions are live and unscripted, the show's soundtrack is created on the spot by a pianist improvising based on what Truman does.

"In games, you never know what the player will choose to do next. The music has to be able to adapt to whatever the player does," said Aaron Marks, a Fallbrook, Calif., composer and co-author of the book "Game Development Essentials: Game Audio Development."

Few composers have made a more complete transition from film to games than Schyman. The classically trained composer, whose credits include the film "Lost in Africa" and the TV series "Magnum, P.I." and "Father Murphy," now makes a good living crafting video game music.

In the early 1990s, intrigued by the potential of a new form of entertainment that lets players participate in the storytelling, Schyman took on his first game project with a title called Voyeur. It was among the first to feature music recorded with an orchestra. Back then, game gigs didn't pay very well, and consoles couldn't support sophisticated audio. After three titles, Schyman returned to scoring for film and television.