A song that cracked the Billboard Hot 100 is now at the centre of a debate over whether it was made by a human or generated by AI. Fenix Flexin's "Rubberz" appears on the chart dated 8 August 2026, and the question of its origins has drawn in a music producer, an AI company, and multiple outlets reporting on the dispute.

The allegations gained traction when producer Medasin posted an Instagram breakdown of what he called AI-style hallmarks in the track, including a "Sonauto.mp3" file suffix spotted in an old Fenix video, as Pitchfork reported on 4 August. Sonauto was the former name of Treblo, an AI music company that rebranded two days before "Rubberz" was released.

Treblo itself added fuel to the fire. The company released a detection tool called "Was This Made With Treblo?" which predicted that "Rubberz" was "very likely Treblo" in origin, according to Wired. Treblo's site claims the tool has a microscopic likelihood of false positives. Its code is available under an open-source licence on GitHub but has not been independently reviewed.

The detection tool also flagged similar results for songs from a new album by Tyga, Fenix Flexin's labelmate, Pitchfork reported.

Fenix Flexin, a former member of the 2010s West Coast rap crew Shoreline Mafia, denied the allegations on X. He said he recorded "Rubberz" the same way he records all his music, with the only differences being auto-tune, reverb, and what he described as his fake UK accent. Pitchfork's Alphonse Pierre had already noted the accent shift in early June, writing that it was ridiculous for an L.A. rapper known for twerk anthems and prescription drug punchlines to now pretend he grew up on the streets of Manchester.

Treblo co-founder Ryan Tremblay told Wired that someone appears to have used Treblo's model to find a sound that millions of people connected with — an acknowledgement that stops short of confirming the track was AI-generated.

Euronews published its own examination of the case on 4 August, framing the dispute around a broader question: whether fans and artists can reliably tell when music is AI-generated.

For now, the claim rests on a tool made by the same company whose technology is alleged to have been used. Treblo's classifier has not been vetted by outside researchers, and Fenix Flexin has offered a human explanation for every element listeners have questioned. The chart, meanwhile, has already counted the song — the Billboard Hot 100 measures consumption, not provenance, and "Rubberz" is on it.