Directed by Brady Corbet. Starring Natalie Portman, Raffey Cassidy, Jude Law, Stacy Martin, Christopher Abbott, Willem Dafoe. 114 mins. In cinemas now.

In Brady Corbet’s audacious, explosive and knowingly ridiculous Vox Lux, Natalie Portman embraces and elevates the persona she created during her hilarious SNL rap sketch, playing a swaggering, mercurial pop star diva.

After surviving a school shooting and writing a heartfelt ballad about the tragedy, 14-year-old Celeste (initially played by Raffey Cassidy) becomes an overnight sensation, instantly plunged into a world of fame and excess.

Not that she was resistant – Celeste exudes an ambition and assuredness at odds with her fragile physicality – but what teen can process that level of both trauma and media attention without becoming lost? And what nation? Corbet skilfully combines these inextricably linked questions.

Celeste isn’t just a girl who became famous; she’s a young person whose family was “on the losing side of Reaganomics”, and as she comes of age around 9/11, her “loss of innocence strangely mirrored the nation’s.” As Celeste becomes internationally famous, she ceases to be a person – which is where Portman comes in, replacing Cassidy’s quiet performance with one of exaggerated indulgence.

Selfish, abrasive and needy, she’s all toddleresque id. Watching her inflict paranoid rants on her daughter or have explosive tantrums before being asked to publicly provide insight into mass violence highlights the absurdity of fame. As the final act becomes a concert film, Celeste finally seems comfortable. When your life has become a performance, the stage becomes home.

In this fascinating, darkly funny and operatic examination of fame, Corbet’s philosophy echoes Celeste’s: “You wanted a show. I’ll give them a show.”.