Natalie Portman Didn't Realize 'How Hard' Pop Stardom Was Until 'Vox Lux'

Natalie Portman
Atsushi Nishijima

Portman portrays pop star Celeste in Vox Lux.

As Celeste in Vox Lux, out Dec. 7, Natalie Portman gives a 13-minute stage performance worthy of all the divas her character would appear to be modeled after. Her supersized ego rivals Madonna's, and her android aesthetic, coupled with fans she refers to as “little angels,” overlaps more than a bit with a certain fame monster. Even so, Portman, 37, insists that her character “is clearly not based on any of those people.” Writer-director Brady Corbet has created a unique celebrity in Celeste: a pop sensation who survived a Columbine-era school shooting only to find herself on the verge of a breakdown 20 years later. Portman performs five original songs in the film, all of which were co-written by Sia and, months after wrapping, remain stuck in her head.

What surprised you about playing a pop star?

I didn't realize how challenging squatting in stilettos is. You really need to be in incredible shape. And I never thought about how hard it is to know what to do with your microphone. Even just knowing all the lyrics and being able to dance at the same time is a skill.

Did you watch the Lady Gaga documentary Five Feet Two or Amy or Madonna: Truth or Dare to prepare?

I watched all of them. They were really helpful with the details. You understand what the lifestyle is like, how demanding it is. People expect you to be who they see in performance.

Did you entertain dreams of being a pop star when you were little?

I definitely remember dancing around the playground with my friends when I was 5 or 6, doing all the moves to Madonna's “Material Girl.” But I was really obsessed with Juliana Hatfield when I was 13. I used to go to every single one of her shows and scream and cry when it was over.

You've rapped in Saturday Night Live digital shorts. How did you feel about actually singing?

I remember asking Brady, “Don't you want to, like, hear me sing?” He said it doesn't matter, that's kind of the point. If you can basically carry a tune, they can do a lot of magic to make it sound like a great song. What you hear is not the raw track, I can promise you.

Was the final performance as much fun as it looks?

We actually filmed that in my hometown. A new studio [opened in Syosset, N.Y.] on Long Island around the corner from where I went to high school. My guidance counselor, who I’m still good friends with, came with her kids and her friends, and they were in the audience. And we stayed at a hotel where I went to every bar mitzvah growing up. It was really funny to come full circle.

This article originally appeared in the Dec. 8 issue of Billboard.