Fenix Flexin’s defense of “Rubberz” has changed shape — from a flat denial of AI to a narrower argument about how the hit was recorded. The shift has only sharpened the questions around one of music’s most conspicuous AI controversies.

The dispute began as producer Medasin publicly argued that the ’80s-styled track had been made with Treblo, formerly known as Sonauto. Fenix pushed back, posting purported session material and insisting the song came from people working in his living room with conventional software.

Then Treblo released an open-source classifier designed to identify music generated by its own model. The company said the tool gave “Rubberz” a “very likely Treblo” result with high confidence; it also reported a false-positive rate of less than one in 10,000. CEO Ryan Tremblay went further, saying the released audio was generated “almost entirely by our model” — potentially making it the first known AI-generated song to reach the Billboard Hot 100.¹

Fenix’s earlier public position appeared unequivocal. Asked on Hot 97’s Mornings With Mero whether AI was on the song, he said there was “no AI on it,” according to reporting on the episode.² But in a later Instagram reply, he recast the dispute: “never said I didn’t use AI,” he wrote, adding that AI had “nun to do w recording process.”²

That distinction is now the heart of the clash. Treblo’s account suggests a largely model-generated recording; Fenix’s new explanation leaves room for AI as a tool while contesting its role in the recording process. Critics, including Medasin, have argued the posted sessions did not settle the question — and may themselves have been constructed with AI-assisted audio tools.¹