Steven Soderbergh could hardly have put himself in better hands when he tapped Cliff Martinez to score “Traffic.” After all, the Bronx-born composer knows the director’s musical taste as well as anyone, having scored such Soderbergh pics as “sex, lies and videotape,” “Kafka,” “King of the Hill,” “The Underneath” and “The Limey.”

“Steven generally doesn’t like hummable melodies,” says Martinez. “He likes repetition, sonic signatures that connect with his characters. It can be a challenge to manage.”

But Martinez has managed it, with a moody, eclectic, synth-heavy score appropriate to “Traffic’s” wide-ranging locales. Most notable, perhaps, is the music Martinez wrote for the film’s Mexican scenes.

“Mexico has more of a sonic identity than the other places in the film,” Martinez says. “It’s vaguely exotic, vaguely ethnic sounding. There’s also more of a rhythmic sense. Steven gave the Mexican scenes a very striking look, to me the most stylized part of the film. My music lends those scenes atmosphere even more than drama or emotion.”

Martinez says that Soderbergh brings him into the filmmaking process early, which is not always the case for composers. Yet according to Martinez, the director “wants to sidestep the conventional use of music.”

“Steven engages his audience by not spoon-feeding them,” Martinez says. “He lets audiences draw their own conclusions, and in that way, he pulls in his audiences. For instance, he doesn’t want romantic music for romantic scenes. He doesn’t want music to explain the emotional aspects of a film in a traditional way.”

So what makes Martinez’s music unusual? “To an extent, my score, which is sparse, tells you what the characters are thinking and feeling, but it mostly acts as a non-specific energy source. And sometimes the music goes in a direction opposite from what people are expecting.”