That’s assuming, of course, your long-lost brother was the guy in charge of the orchestra at this year’s Academy Awards telecast -- you know, the man who struck up the band when an Oscar winner’s acceptance speech went over the allotted time -- and that he has scored some of the biggest and most famous films, TV shows, and video games of the last decade.

Over the past 10 years, as Giacchino’s résumé has swelled, so has his Hollywood family tree. Giacchino has found brotherhood not only with Docter but also with icons such as Steven Spielberg and relative upstarts like J.J. Abrams, using oboes and French horns to help the master filmmakers texture their stories with emotion and excitement. This year, Giacchino, who already scores myriad television programs, will compose music to punctuate three summer blockbusters: Up, the Will Ferrell–helmed remake of Land of the Lost, and the much-ballyhooed relaunch of the Star Trek franchise.

The workload is enough to make even the slickest of Hollywood moguls tremble in their box offices, but Giacchino’s calm, accommodating demeanor and expert knowledge of film history has quickly made him an A-list contributor in feature-film postproduction. It only makes sense, then, to place Star Trek’s sacred four-note opening in the hands of this ardent film fan.

“As a kid, I loved the original series immensely, and some of my favorite music has come from the first Star Trek films,” Giacchino says. “It’s exciting -- and at the same time frightening -- to be a part of something from your childhood.”

WHILE GROWING UP in Edgewater Park, New Jersey, Giacchino always wanted to work in the film industry -- but at age nine, he was a director rather than a composer. “I had a Super 8 camera, and I spent a lot of time making movies starring my brother,” he says.

These days, the stars he works with have considerably higher wattage, and Giacchino has passed the home-movie hobby down to his son Mick. Giacchino recalls the time he introduced Mick to John Williams, the Oscar-winning composer for Star Wars, E.T., and Jaws. “John asked him who his favorite composer was, and Mick answered, ‘Erich Korngold,’ “ says Giacchino. The nine-year-old and the Hollywood legend then went on to discuss the challenges of performing Korngold’s 1938 Oscar- winning score for The Adventures of Robin Hood. “John and I were both blown away,” says Giacchino, laughing.

Yet it’s that same kind of immersive knowledge that has directors and producers lining up to collaborate with Giacchino. “One of the reasons we decided to work with him is that Up has a real nostalgia aspect to it,” says Pixar’s Docter. “It takes place starting in the 1930s and then moves forward through the ’40s and ’50s. … We wanted to hark back to those older scores in all those classic Hollywood films, and Michael really gets that.”