A. G. Cook on Scoring Charli xcx’s ‘The Moment,’ Using ‘Brat’ Songs Sparingly and Why ‘Mulholland Drive’ Was a ‘Very Conscious Influence’

When it came to finding a composer for Charli xcx’s mockumentary “The Moment,” no one made more sense than her longtime producer and friend A. G. Cook. Though he’d never scored a feature before, his fingerprints are all over “Brat,” Charli’s seminal 2024 album that became a lime-green, party-girl phenomenon and serves as the backdrop for the Aidan Zamiri-directed film.

In “The Moment,” which premiered at Sundance Film Festival before opening in select theaters on Friday, an alternate-reality Charli must choose between standing by her art or selling out when a sinister director (played by Alexander Skarsgård) is hired to make her concert movie. But “The Moment” mostly avoids songs from “Brat,” relying instead on an electrifying score from Cook that evokes — though doesn’t directly pull from — the sonic landscape of the album.

“I’ve been working with Charli for so long that, reading the script…