The first AI song to crack the charts just got dobbed in by its own app.

Adam Spencer
13 hours ago
5 min read

1990 Milli Vanilli were exposed as Mimey Vanilli. The Monkees were actively banned from playing on their early albums. Marvin Gaye’s estate took Robin Thicke and Pharrell to court over blurred lines and won. Pop is full of controversy. Well 2026 doesn’t disappoint … with an AI twist.

(First published on my Substack where you can get #NerdNews, marvellous maths and general geekery.)

(“Two turntables and an LLM”: created by the author via Dall-E)

This charming model.

On 5 June a Los Angeles rapper named Fenix Flexin dropped RUBBERZ, a two minute synth-pop dirge that normally would have made a minor splash and then disappeared. But something smelt, or should I say sounded, a bit off.

See FF came up through the West Coast rap crew Shoreline Mafia. Yet suddenly, as Wired’s Dexter Thomas explains, Fenix's usually nasal, East Hollywood drawl was coming out on RUBBERZ "closer to a very chipper Morrissey". This both raises suspicions and gives me licence to go big on Smiths puns in these NerdNews headings.

It charted well regardless, hitting as high as number 58 on the Billboard Hot 100. Those sales and millions of video views saw it feature on several US songs of the summer lists.

But the kids were suspicious despite Fenix’s blanket, if grammatically challenging denials.

"No sirrrrrrr, recorded same as all music I do! Only difference is auto-tune reverb and me using my fake uk accent lol." — Fenix Flexin, On The Radar.

His producer Purps on the Beat (who calls their kid Purps?) backed him in.

For two months it went nowhere. The track did not trigger the most popular AI music creation and detection programs and it seemed we’d never know the truth.

Then bang.

Bigmouth strikes again.

Along came Texas-based producer Grant Nelson, who you probably know better as Medasin. Who am I kidding, I’d never heard of him either. But I did when he dropped on Instagram “The reckoning of Fenix Flexin and Purps”.

Medasin makes three points.

First, he doesn’t cite the AI-music monster apps Suno or Udio, but a smaller platform called Treblo. And crucially Treblo was named Sonauto until a couple of days before RUBBERZ was released.

Second, he links the song to Sonauto via a freeze-frame from one of Fenix's own Instagram stories teasing the new sound. What’s that if you look closely: a file name ending in Sonauto.mp3.

And the clincher. Medasin gave Treblo a couple of obvious prompts, eighties synthwave and rapper lifestyle. Guess what popped out? A song that so closely resembled RUBBERZ it featured matching rhyme pairs and near-identical lines.

“It very consistently spits out exact specific bars from RUBBERZ. Way too many, way too often, for it possibly to be a coincidence.” — @Medasin, Instagram.

Fenix posted what he said was the original studio project file. Producers in the comments said it looked like the output of a stem separator, the tool that pulls a finished track apart into drums, bass and vocals. He deleted the post within hours and has not explained why.

Medasin told WIRED the coincidences made it a mathematical impossibility that Treblo was not involved.

("Fenix got fingered?”: created by the author via Dall-E)

I’m not across the big M’s mathematical credentials. But his case adds up to me.

Heaven knows it's AI now.

In steps Wired journalist Dexter Thomas, whose piece first alerted me to RUBBERZ-gate. Parenthetically, I note Dexter has a PhD in Japanese hip-hop, which pretty much ensures he is never short of conversation starters.

Thomas ran the experiment himself. Feeding Treblo similar prompts, he kept getting songs that shadowed RUBBERZ. The engine seemingly has tics, including a particular rhyme pair and an unhealthy obsession with rings, glass and pockets.

He suggests these are Treblo’s versions of ChatGPT’s predilection for em dashes, and the now hackneyed “it-is-not-X-it-is-Y” construction.

Ask me, ask me, ask me.

Finally Treblo rolled on Fenix.

Late on Sunday night the company released an online detector for its own output, named "Was This Made With Treblo?”.

Feed it RUBBERZ and you get “very likely Treblo”. A July release from the rapper Tyga is rated “likely Treblo”.

Now these are verdicts from Treblo's own unaudited tool, so it’s not take-it-to-the-bank certified. But Fenix, Tyga, it doesn’t look great.

Cofounder Ryan Tremblay didn’t exactly throw these artists under the bus. He told WIRED it looked like someone had used their model to find a sound millions of people loved, and that this was exciting.

Our man Fenix has still confessed to nothing. Perhaps he is too busy swipin’ cards and stackin’ chips?

Stop me if you think you've heard this one before.

So why did nobody catch this for two months?

Take HumanStandard, one of the better detectors. It cleared RUBBERZ. Twice. Then founder Rasha Rahman got a tip about Treblo, scraped a thousand of its tracks, retrained his model, and ran the song again. Fully AI generated.

We are still in the early days of AI-detection and a detector only knows the generators it has been trained on. Treblo is small and new.

So ironically, the outfit best placed to catch a Treblo fake is Treblo, because it owns the data nobody else has. This raises an awkward question. It could have analysed RUBBERZ the moment suspicions swirled. Instead it shipped the webpage three days ago, two months into the chart run.

What difference does it make?

This won’t be the last time art gets exposed as being made with AI. What I wonder is, will people care?

Medasin, who admits the song was stuck in his head for a month, does not argue that AI has no place in music. He wants artists to say so, and told WIRED that profiting from the deception strikes him as unethical at a deep level.

"We need transparency about what is and isn't AI generated" — Medasin, producer.

When it comes to AI and culture, I think it will depend very much on the genre. I’m the first to admit the images accompanying NerdNews are AI generated. I don’t have the skills, nor the budget, to pursue alternatives.

I’d rather read non-fiction from a human hand that I feel didn’t land the ending, over perfectly wrapped up but slightly soulless AI fare. But if I’m reading a textbook on human anatomy, I’d prefer a 100% accurate AI assembled atlas to one that may contain human error.

I want my cello player to be human and potentially miss a note. But the mid tempo European techno that I’m listening to right now as I write this, could well have a heavy AI hand and I don’t know if I’d care.

And of course the provenance of individual cultural items sits distinct from concerns that AI ‘culture-bots’ could drown out human artists in a tsunami of slop.

Have a listen and see whether you would have picked it.

https://www.youtube.com/watch?v=Hl5_Lc6b3AU

Most people did not, which is rather the point. The first fully synthetic song to crash the charts was always coming. Nobody had it turning up in a fake British accent doing Morrissey.