Finneas O’Connell and his sister Billie Eilish are now big names in music. They’re in the spotlight for their latest hit, “What Was I Made For?” from the “Barbie” movie, grabbing Grammy nods for both “Record of the Year” and “Song of the Year”.

Their magic happens in Finneas’ small basement studio in LA. That’s where they cooked up “Ocean Eyes” back in 2015, the track that skyrocketed them to fame.

Turns out, a lot of their hits, “What Was I Made For?” included, spark up when they’re just hanging out, jamming on the piano.

“We sit here, co-piloting. The microphone that’s over your shoulder. It’s like a boom mic, and she’ll just swing it around,” Finneas said.

“I’m fairly certain that was how we wrote ‘Barbie’ was, I was sitting at the piano. And she was sitting here or maybe on the couch with the mic,” he said.

Director Greta Gerwig needed a special “heart song” for Barbie in the movie. She let Eilish and Finneas watch 40 minutes of the film to get the vibe. They got right on it, though they tweaked some parts of the first song they came up with. 

“We wrote the whole song in like 45 minutes with a bad, with a terrible bridge that we ended up, um,  rewriting,” said Finneas. 

Their tune played all through the movie, hitting its peak in Barbie’s big emotional moment. Their hard work paid off – they won Best Original Song at the Golden Globes last weekend. Finneas said watching their song blend with the movie scenes was “so powerful.” 

But some projects were tougher. Finneas shared that making the theme for the James Bond movie “No Time To Die” was tricky. Teaming up with the famous composer Hans Zimmer in London, they really felt the heat to match the epic James Bond theme legacy.

“James Bond has such an ethos and a sort of a signature thing. That if — if you fail, you really, you really fail. You really miss the mark,” Finneas said.

They ended up with a song that didn’t just wow the critics, but also scored them a Golden Globe, a Grammy, and an Oscar.

Their story started when Finneas was 18 and Eilish just 13, in a home filled with music. Their mom, Maggie Baird, wrote songs too.

Now at 26, Finneas has bagged eight Grammys already. He dropped his first solo album, “Optimist,” in 2021 and he’s not hitting the brakes. He’s busy scoring Alfonso Cuarón’s new Apple TV+ series “Disclaimer,” and is also helping Eilish with her latest album, their third collab.

Finneas said, “I think that it’s the closest I am with Billie to like total trust of anyone and total vulnerability. I’m sure there’s something that she would be embarrassed to say in front of me, but not much.”