Fenix Flexin’s “Rubberz” is currently ranked No. 58 on the Billboard Hot 100, having accumulated 7 million views on its music video since its June release.
The track presents a specific set of contradictions. Lyrically, it features boasts about cash and jewellery alongside bars that function as double entendres for braggadocio and depression. Musically, it is a synth-pop tune rather than a rap song, fitting a moody 1980s playlist. Since dropping, the song has become the focus of accusations that it was generated entirely or partially by artificial intelligence.
The debate intensified this weekend when an independent producer claimed to identify the tool used by Fenix and suggested his labelmate, Tyga, also used a generative app for his own 1980s-themed tunes. The creators of that app, Treblo, have now confirmed the suspicion. Their new built-in detector flags both songs as likely AI-generated.
The Voice Issue
Suspicion of Fenix Flexin existed from the beginning. The track represents an unusual genre shift for the artist, and the vocal performance does not match his usual delivery.
Raised in East Hollywood, Fenix possesses a somewhat nasally, congested voice that was recognisable during his debut with Shoreline Mafia in the late 2010s. The voice on the June 5 release of “Rubberz” is completely unrecognisable. It is brighter and crisper, with an accent that sounds closer to a very chipper Morrissey.
Both Fenix and the credited producer, Purps on the Beat, have denied using AI. Fenix told Channel 5 that he freestyled the lyrics. In comments on an On the Radar performance, he replied to accusations: “No sirrrrrrr, recorded same as all music I do! Only difference is auto-tune reverb and me using my fake uk accent lol.”
Not everyone accepted this explanation, but there was no proof otherwise. As the summer continued, music media debated the origin of the track. Standard AI music detectors did not flag it, Fenix denied it, and the song continued to rack up plays. Fans had to remain comfortable with the question being unresolved.
Then, the situation shifted suddenly. On Thursday, a producer named Medasin posted a video claiming to have identified how Fenix created the track.
The tool was not Suno or Udio, the two most prominent generative AI tools. Medasin stated Fenix had used a lesser-known app called Treblo. His accusation was methodical. He noted the app was previously called Sonauto until two days before “Rubberz” was released. He showed a screenshot of an old Instagram Story from Fenix teasing his new 1980s sound. A freeze-frame and zoom revealed a filename on the screen with the suffix “Sonauto.mp3.”
The most compelling evidence came when Medasin demonstrated he could use Treblo to create a similar track. Using tags like “80s synthwave” and prompting the app to write lyrics about a “rapper lifestyle,” he generated a song with a similar sound. The lyrics bore more than a passing resemblance to “Rubberz.”
For example, Medasin’s prompt generated the line “Diamond chains hanging heavy,” while “Rubberz” contains “Now I bought a heavy diamond chain.” Medasin’s song included “I see your face in the champagne bubbles,” whereas Fenix’s has “Still seeing your face in the glass.” Both songs feature a permutation of “pockets thick” and mention “plastic smiles.”
“There’s just way too many coincidences,” Medasin said in an interview with WIRED. “It is just a mathematical impossibility that he did not use Treblo.”
Curious to test the claim, I attempted to re-create a “Rubberz”-style song. Entering tags like “80s synthwave” and asking for rap lyrics produced not only a similar sound but similar lyrical structures.
In my first attempt, I generated a song with the couplet “Rings on every finger / Leather seats and cedar scent linger,” an almost mirror duplicate of the “Rubberz” line “Gold rings on my fingers / Still your perfume lingers.” I continued generating songs. Even with slight variations, combining an “80s” tag with a prompt for “rap lyrics” yielded similar results.
Whereas ChatGPT seems to prefer goblins, em dashes, and “it’s not X, it’s Y” constructions, Treblo’s engine appears obsessed with “finger/linger” rhyme pairs, references to rings and glass and pockets, and song constructions featuring a thematic transition from night into day.
Medasin stated his revelation occurred a month ago but he kept it quiet, expecting a journalist to connect the dots for the public. This happened on a smaller scale, perhaps most thoroughly on an AI music news site called Zinstrel, but it never gained traction. Medasin’s video was the first to capture attention.
By Thursday afternoon, it appeared Medasin had struck a nerve. Fenix posted a video on his Instagram page showing what he claimed was the original project file for “Rubberz.” If authentic, this would serve as proof the song was not AI, created from scratch in a studio.
Music producers immediately jumped into the comments. Many claimed the project file looked suspiciously like someone had taken an existing song and used a “stem separator” to extract rudimentary components like bass and drums. This would point back to the track being an AI song they could not create themselves.
Hours later, Fenix deleted the post. Neither he nor Purps on the Beat have addressed the “evidence” video since, or why it was taken down. Requests for comment sent to both by WIRED went unanswered.
Then, another development. Two days later, on Saturday, Medasin dropped another video alleging Tyga’s new $TARFACE project is also at least partially using Treblo. He started with loose connections: videos of Tyga and Fenix together, both on the same label, and the same sudden shift from rapper to 1980s crooner. He also ran a Tyga song in a new AI music detector a friend is developing, and it was flagged as AI.
It is more convincing to hear directly from Treblo itself.
“Someone appears to have used our model to find a sound that millions of people connected with,” Treblo cofounder Ryan Tremblay said when asked for comment, “and that’s exciting.”
Tremblay stated Treblo had not previously spoken to Tyga or Fenix, and the company was not even aware “Rubberz” existed until after it hit the Hot 100.
Asking Treblo about individual songs might not be necessary in the future. Late Sunday night, Treblo published a page titled “Was This Made With Treblo?” It is a Treblo music detector. “We also think listeners should know what they’re hearing,” a blog post explains, describing it as a tool “tuned to detect songs made with Treblo with little to no modification.”
Feeding “Rubberz” into the tool returns a result of “Very likely Treblo.” Running a track Tyga dropped in early July returns a result of “Likely Treblo.”
The rate of false positives, Treblo’s site says, is under one in 10,000; a fraction of a percent. The detector’s efficacy has not been independently reviewed, but Treblo has released the code under an open source license so anyone can inspect it and test it.
Requests sent by WIRED to Tyga’s label for comment were not returned.
Industry Reaction
The timing coincides with a trend of platforms making gestures toward AI-generated content. The same day Medasin posted his first video, LinkedIn rolled out a new feature: a “seems like AI” button that allows users to flag AI slop in posts. Two weeks ago, Substack released a new feature that purports to detect AI-written newsletters. Tidal has blocked monetization of AI-generated music, and while Spotify does not have an AI tagging feature, there is a crowdsourced tracker where listeners can report slop.
The proliferation of image and video generators over the past few years has provoked worries about the spread of machine-made content and misinformation. A bipartisan AI Labeling Act in the US Senate has been suggested as a partial solution: forcing platforms to visibly label AI-generated content so it is clear whether online content is real or not. “People deserve to know,” one senator told Politico.
What we should have anticipated was that there would be people who do not want to know. People who would get angry if you ruin the fantasy.
The comment section of Medasin’s first video is full of this: people saying they like “Rubberz” anyway, that they do not care if the song is AI. They argue AI is the future and that Medasin is just jealous Fenix thought of it first.
Medasin says he was not surprised by the reaction. He admits he liked the song when he first heard it and still somewhat enjoys it in an ironic way. “It’s catchy, and it was stuck in my head for a fucking month,” he says. So why risk a bunch of people looking at him like he is the guy in the conspiracy board meme?
Ultimately, Medasin says he thinks there can be a place for AI in music, even if he does not like it personally. But he wants artists to tell the truth, so listeners can decide for themselves.
“This is, like, a critical moment in music history,” Medasin tells WIRED, “and I have very, very deep respect and love for the journey of musicians and humans and human experience being celebrated and present in music.” He decries anyone who would be deceptive about that and profit off of it. “It is unethical to me on a very spiritual level,” he says.
Music fans spent half the summer arguing over whether a surprise hit song was synthetic. It looks like they have an answer. Now they just have to decide how much it matters to them.
