Giacchino’s techno sound helped Alias’s main character, Sydney Bristow, trot the globe each week, and it begot the jazz-infused score for Pixar’s 2004 blockbuster, The Incredibles. Abrams and Giacchino then teamed up for TV’s Lost, a dark, nuanced drama whose score seemed to bring its mysterious island setting to life. Though Giacchino writes the music for films months in advance, he makes up the Emmy Award– winning music to Lost on the fly, recording each episode’s composition while watching it only a few weeks ahead of the airdate. “That show, to me, is all about just being emotionally reactive to what’s happening,” he says.

Despite the near-constant demands of working, sequentially, on Alias, Lost, and Abrams’s Fringe, Giacchino has been able to put his musical stamp on films as varied as the big-budget Mission: Impossible III, the silver-screen adaptation of Speed Racer, and the Grammy-winning and Oscar-nominated Pixar-animated feature Ratatouille. “There’s always a movie to score out there if you want one, but, for me, it’s about more than that,” he says. “It’s about loving what you do and finding more challenging ways to do it.”

This year, Giacchino was presented with a challenge that few film composers are ever offered: Conduct and compose for the Academy Awards. Hosted by throwback showman Hugh Jackman, the event promised some big changes to the previous format, which had grown stale over the years. “We decided to take the orchestra out of the pit and put them on the stage,” Giacchino says. The move gave the set a closer, more intimate, nightclublike feel for the audience and also put the music at the forefront of the night.

“We had this host, Hugh Jackman, who could sing and dance, so we thought, ‘Why not work with that?’ “ he says. But the opening number quickly proved to be more difficult than expected because Giacchino, facing the orchestra, had his back to Jackman, who was dictating the pace. “There’s nothing like live television,” Giacchino says. “I’ve never done anything like it before.”

Yet for one night, one of Hollywood’s least-recognizable players was its most powerful, able to cut acceptance speeches short or trim away half-baked acts. Giacchino kept the show running like a train conductor, proud to introduce Spielberg with the theme to The Lost World, of all things. “I don’t think he noticed, but I knew,” Giacchino says. “It all kind of came full circle.”