Treblo's own AI detector confirms Fenix Flexin's 'Rubberz' was likely generated

The murky origins of Fenix Flexin’s “Rubberz” just got a lot clearer — and it’s a nightmare for the rapper’s denials. Audio software company Treblo released an open-source AI music classifier on Monday, and they immediately turned it on the controversial track. The result? The company says “Rubberz” is “very likely Treblo” with “high confidence,” essentially calling the song a near-total generation from their model.

This isn’t just internet speculation anymore. The classifier, which Treblo claims has a false positive rate of less than 1 in 1,000, gave the song an extremely high probability score. CEO Ryan Tremblay leaned into the controversy, telling The Verge that the analysis indicates “the released audio was generated almost entirely by our model.” He framed it as a milestone, adding it would be “the first known AI-generated song to reach the Billboard Hot 100.” That’s a provocative claim — and one that puts a prestigious industry chart in the middle of a authenticity debate it’s not remotely prepared for.

Fenix hasn’t budged. He’s been posting grainy clips of what he says are the original recording session files, a defense that producer Medasin publicly dismantled. In a now-expired Instagram story reported by Stereogum, Medasin argued Fenix simply used an AI stem separator to fabricate the session footage from the AI-generated track. It’s a technically savvy counter-allegation that makes the denials look increasingly flimsy.

The whole saga feels like a watershed moment that the music industry has been dreading. Detection tools are now being built and weaponized by the very companies that create the generators, turning their models into both the crime and the detective. The real question isn’t whether Fenix used AI — Treblo’s classifier has made that debate feel settled — but what Billboard, labels, and streaming platforms do when the next AI-generated hit inevitably lands, and the creator doesn’t even bother to hide it.