Michael Giacchino is a widely respected film composer, with an Oscar and a Grammy for “Up” and an Emmy for “Lost,” as well as a Grammy for “Ratatouille.” He is stirring up Oscar buzz again with his score for Fox Searchlight’s “Jojo Rabbit,” written and directed by Taika Waititi. Giacchino talked with Variety about the challenges of that film, as well as his expanding workload, including directing an animated “Star Trek” short. He’ll appear Oct. 18 in concert at London’s Royal Albert Hall, and at the “Coco” music event at the Hollywood Bowl on Nov. 8-9.

How tricky was it to catch the tone of “Jojo Rabbit”?

I didn’t want the music to be funny. The bulk of the movie has this huge heart, especially in the character of Jojo himself, and I wanted to make sure I wasn’t adding to the zaniness. I wanted to underline the emotional component. For me, it’s a devastating story but in the end an uplifting one. With everything we’re going through now, it felt like something important to be a part of.

The opening music is daring, with a bouncy children’s choir.

I wanted to create a theme that could start out as one thing and then become something else. In the beginning, Jojo’s theme is essentially a Nazi march. If you had translated lyrics about what those kids are singing, they seem to be all praising the Hitler Youth paradigm and what is good about fascism. My hope is that by the end of the movie, you would have a completely different interpretation of that song. I wanted to create a transformation of Jojo, who wants to sing the lyrics proudly as a Hitler Youth, but by the end of the film wants to sing as someone who is against fascism. The lyrics were written by an incredible songwriter, Elyssa Samsel.

What was your biggest concern?

The first time I saw this film, I was so excited to be part of it, but terrified: How do I make this work? Taika went out on a limb to do a film like this, and I didn’t want to mess it up. I wanted to make sure the movie kept an emotional center and had a solid theme that would carry through and help tell the story.

The film has some abrupt transitions, from intimate scenes to action to comedy.

It was tricky making those moments work and making sure we weren’t overstating the storytelling. So many films go too far when they use music, because they fear the audience won’t understand something. This was about “How can we stay restrained as long as we can, until we need a moment that’s big and boisterous?” I wanted the core to be a piano piece, very simple, something that sounds like it could have been played on a record player at the time.

What’s coming up?

I’m in the middle of directing an animated “Star Trek” short for CBS. It will air first on CBS All Access. I had directed “Monster Challenge,” a short film about a year and a half ago with Patton Oswalt and Ben Schwartz, which premiered at Fantastic Fest. After that short, Alex Kurtzman, who is in charge of all things “Star Trek,” called to ask if I wanted to direct a “Star Trek” short. Of course I did! I grew up making movies and went to film school. I sort of fell into music. Now I’ve been trying to get back to making movies too.

What’s your all-time favorite film score? 

The original “King Kong,” by Max Steiner. And Max Steiner’s score brought those images to life. The score was massively successful on its own, and it also created the template for how we approach writing music for movies. Prior to that, it was “chase music” during a chase scene, “love music” during a love scene, and so on. Max Steiner applied thematics to characters in the way that opera composers did. That was the thing that made me realize, “Oh! Music is a storytelling device; it’s not just background.”