One night last December, weary from a busy week and the impending doom of winter, I hurried into Carnegie Hall to witness Cameron Winter. The Geese frontman was marking the end of a breakout year with a series of rapturously received solo acoustic shows, drawing the penitent for whom the 23-year-old’s primordial voice struck some kind of destabilizing natural frequency. I had bought the ticket months earlier, after being hypnotized by Winter’s beguiling debut solo album, Heavy Metal, and sat transfixed in the rafters, far from the Brooklynite’s lanky, stygian presence before a single piano.

So far, in fact, that I assumed the maybe-camera that came on stage at one point was a bit, perhaps a jab at our incessant need to film things from a very deadpan celebrity whose only non-music interlude that evening was to wordlessly stand, stretch and mockingly fight with the stage door, as if trying to escape his own momentous show. I emerged from the event teary, charged by what felt like a communion across time, and confused by a friend’s text: “can’t wait for the cameron winter PTA doc”.

PTA, of course, is Paul Thomas Anderson, the acclaimed film-maker and, it turns out, one of five camera operators (including Benny Safdie) working that evening to capture Winter’s masterly performance on film. The resulting project, Cameron Winter at Carnegie Hall, which premiered this week at the New York Film Festival, is very much not a bit. Shot on 35mm, with coloring so luscious even the scaffolding outside Carnegie Hall looks dignified, this 75-minute concert film manages to preserve most of what made that evening so special — the stark contrasts of Winter’s music, the mesmeric force of his baritone vibrato, the vanishingly rare power to make an audience implicitly agree to collectively ignore their phones and focus, for as long as necessary. The auteur’s second concert film is an immediate classic, memorializing, in the medium of said classics, a performance that felt less like a concert than an ancient ritual and proclamation, a stake in the ground of a young but blazing career.

Fittingly for a subject whose only address all evening was a post-encore “thank you for coming, everybody,” Anderson dispenses of virtually all bells and whistles; save a minute of exterior shots and ticket scans plus a couple of finely wrought transitions, Cameron Winter at Carnegie Hall is, well, just that – the concert, straight up and gorgeously recorded, Winter’s woozy vibrato and intensity on the keys so seemingly unmediated that I felt compelled to applaud after each of the 12 songs. (The film’s brilliant music production was done by Ariel Rechtshaid, a Grammy winner for his work on albums by Vampire Weekend and Adele; a live album is soon to be released.)

Cameron Winter. Photograph: Christian Sinibaldi/The Guardian

The on-stage camera notwithstanding, Anderson et al largely stay out of the way, appearing to lurk throughout the cavernous theater, from my rafter seat to the aisle to the piano bench, like one of Winter’s many shadows, themselves filmed to haunting effect. Depending on the scene, the stark shifts in light, and the angle of piercingly close shots on his face, Winter appears either 20 or 60 – all the better to get hit by his absurd yet evocative lyrics, such nonsense as “the beach ball cathedral dimpled like a sea fly swarming”, “until the conga line behind me is a thousand chickens long” and, most evocatively for a largely secular New York audience, “god is real.”

Some elements of the show did not fully translate to film – the ecstatic, slyly humorous decision to bring the lights up on that “god is real, I’m not kidding this time!” so one could see other beaming faces, was the show’s acme but a film footnote – though Anderson and co were able to capture the quiet that Winter wields to such seismic, spellbinding effect, as well as the rapt audience receiving it. Like Winter’s music, the film itself appears at once sumptuous but austere, raw and intuitive yet precise.

This is, of course, a document for the faithful, the people who either already adore Winter’s singularly striking voice or are naturally predisposed to. Those who don’t will find no other hook – no interview nor testament nor voiceover nor crowd work – to bring them in. But those who do enter will find a exquisitely rendered version of something old and timeless — an interplay of light and shadows and a communion of generations, summoned by a figure of gifts beyond his age, captured for the ages.

• Cameron Winter at Carnegie Hall is screening at the New York Film Festival and will be released in the US on 20 November with UK and Australia releases to follow in 2027