Billie Eilish Covers The Beatles' 'Yesterday' for Oscars In Memoriam

The celebrated songstress made a special musical appearance during Sunday's star-studded ceremony.

Billie Eilish brought her stunning voice and emotionally intimate stage presence to this year's Oscars for a touching special performance during the heartfelt In Memoriam segment.

The 18-year-old songstress graced the stage with a heartfelt cover of "Yesterday" by The Beatles. She sat as she belted out the song's touching lyrics while brother and collaborator, Finneas O'Connell, played the piano.

Before the show kicked off on Sunday, Eilish took to her Instagram Story to announce that she would be performing a cover during the segment.

"Honored to be performing during the in memoriam segment for the oscars tonight covering a song i’ve always loved," she wrote.

Among those honored in the heartfelt segment was NBA legend Kobe Bryant, who died in a tragic helicopter crash in Calabasas, California -- along with his 13-year-old daughter, Gianna, and seven others, on Jan. 26. He was 41.

On top of Bryant's five NBA championship rings, the celebrated star also took home an Oscar in 2018 for Best Animated Short Film for Dear Basketball, which Bryant wrote and narrated. The win made him the first African American to win an Oscar in that category, and the first professional athlete ever to be nominated and win an Oscar in any category at all.

The tribute also had to work quickly to include iconic actor Kirk Douglas. The three-time Oscar nominee died last Wednesday at age 103.

The emotional tribute also remembered a number of other past Oscar nominees, including the legendary producer of Chinatown and The Godfather, Robert Evans, screenwriter Buck Henry -- best known for penning The Graduate and Catch-22 -- Cross Creek and Men in Black star Rip Torn, Blade Runner star Rutger Hauer, French documentarian and Faces Places director Agnes Varda, as well as Pillow Talk actress and singer Doris Day.

Celebrated filmmaker John Singleton was also honored in the emotional video package. Singleton -- who died on April 28 at the age of 51 after suffering a stroke -- made Oscars history in 1992 when he became both the first African American filmmaker and the youngest person ever to be nominated for Best Director at the Oscars for his film, Boyz n the Hood. His work in the groundbreaking drama also earned him a nomination for Best Original Screenplay.

Before the big show, ET caught up with Eilish on the red carpet and she shared that she wouldn't be performing the new James Bond theme song at the ceremony. 

"I can't do that for the In Memoriam," she said. "It's not about me, this is about them and showing love. It's not my thing. It really is true. I don't want it to be about me, I want people to be watching the screen, watching the people and you know."

"I'm really looking forward to being a -- what's the world -- respectful and respecting all the people that have passed this year. That's all I'm here to do," she added. 

When it comes to Bryant's death, Eilish said it still "doesn't make sense" to her. 

"I mean, it's just sad. It's like I don't know what else to say," she shared. "Every time, when we were in rehearsal and they run kind of what's going to be playing, every time I see his face I'm like, what? It's so weird. It doesn't make sense to me. I just got shivers. It's horrifying."

Eilish's performance at the Oscars wraps up her impressive awards season run. Check out the video below for more on her record-setting triumphs at this year's GRAMMY Awards.