'Rogue One' Composer on Facing Down Nerves About 'Star Wars' Gig

— -- You might not recognize Michael Giacchino's name, but if you've seen any big movies in the past few years, you've heard his work.

Starting with his brassy, Bondian music in "The Incredibles," Giacchino scored everything from the third "Mission: Impossible" movie to the successful "Star Trek" reboot films.

This year, he composed scores for the blockbuster "Doctor Strange" and "Rogue One: A Star Wars Story."

So did Giacchino feel intimidated following in the footsteps of legendary "Star Wars" composer John Williams?

"I didn't think about any of that until I was at my first day of recording," he told ABC News. "For fun, I brought up the 'Star Wars' main theme, just to warm up the orchestra. ... The second we started playing that I was thinking to myself, 'What was I thinking? Why did I say yes to this? This is crazy! What if it sucks?!' But because there was so much work to do, I hadn't thought about it until that moment."

Both he and director Gareth Edwards are lifelong "Star Wars" fans and they took the gig very seriously, considering the legacy of "Star Wars" and its iconic music. "... [W]e felt this responsibility to create something that carries it forwards, but also makes it feel like you're at home when you're in that theater."

Giacchino got to realize another dream on the last "Star Wars" film to hit theaters: He suited up as a bad guy, appearing in the film as a Stormtrooper.

"I wasn't scoring 'Force Awakens,' but if you gave me the choice to score 'Force Awakens' or be a Stormtrooper, I woulda chose Stormtrooper, so I got lucky."

"Rogue One: A Star Wars Story" was produced by Lucasfilm, which is owned by ABC's parent company Disney.