Billie Eilish and Finneas O'Connell won the Oscar for best original song.

The sister and brother duo's hit song, "What Was I Made For?" from "Barbie," marked the duo's second Oscar win for best original song. They previously won the award in 2022 for their song "No Time To Die" from the James Bond film of the same name.

During their acceptance speech, Eilish said she felt "so incredibly lucky" and "honored" to take home the award.

"Thank you for this," she said. "I'm so grateful for this song and for this movie and the way that it made me feel, and -- this goes out to everyone who was affected by the movie and how incredible it is."

Other nominees in the category included "The Fire Inside" by Diane Warren from "Flamin' Hot," "I'm Just Ken" by Mark Ronson and Andrew Wyatt from "Barbie," "It Never Went Away" by Jon Batiste from "American Symphony" and "Wahzhazhe (A Song For My People)" by Scott George from "Killers of the Flower Moon."

Ryan Gosling and Mark Ronson took the Oscars stage and delivered an epic performance of "I'm Just Ken" from "Barbie."

During his performance, Gosling was joined by his fellow Kens from the film and got director Greta Gerwig and co-stars Margot Robbie and America Ferrera to join a sing-along from the audience.

The performance also featured Guns N' Roses guitarist Slash, who played on the recorded track.

"I'm Just Ken," which was written and co-produced by Ronson and Andrew Wyatt, is nominated for best original song tonight.

"The Zone of Interest" won the Oscar for best sound.

Tarn Willers and Johnnie Burn took to the stage to accept the award for their work on the Jonathan Glazer film.

Other nominees in the category included "The Creator," "Maestro," "Mission: Impossible - Dead Reckoning Part One" and "Oppenheimer."

Becky G hit the stage and performed "The Fire Inside" from "Flamin' Hot."

She was joined onstage by a choir of young girls during her moving performance.

"The Fire Inside" marks Diane Warren's 15th Oscar nomination for best original song.