Fenix Flexin Treblo “Rubberz” claims now have a new piece of evidence, though not a final answer. Treblo’s newly released music classifier labeled the rapper’s June single “Rubberz” as “very likely Treblo” with high confidence, according to The Verge and Stereogum. The result supports the public allegation that the track used generative AI, but it comes from the company whose product is being identified and does not establish who made the song or how it was produced.
Treblo said it released its open-source Treblo AI Music Classifier on Monday. The tool is designed to identify audio generated by Treblo, formerly known as Sonauto, rather than to detect AI music generally. That narrow scope matters: a positive result is Treblo’s assessment of whether its own model made the released audio, not an independently audited reconstruction of a recording session.
Ryan Tremblay, Treblo’s CEO, told The Verge that the score for “Rubberz” was very high and indicated that the released audio was generated almost entirely by Treblo’s model. His wording stopped short of naming Fenix Flexin as the person who used it: “Someone appears to have used our model to find a sound that millions of people connected with,” Tremblay said.
Did Fenix Flexin use Treblo for “Rubberz”?
The available evidence makes Treblo use a strongly supported allegation, not a settled fact. Treblo’s own detector flagged the song, and producer Medasin has laid out a separate circumstantial case. But Fenix Flexin and the track’s credited producer, Purps on the Beat, have denied using AI.
According to WIRED, Medasin pointed to an older Fenix Flexin Instagram teaser in which a visible filename appeared to end in “Sonauto.mp3.” He also used Treblo prompts including “80s synthwave” and a request for lyrics about a rapper lifestyle to generate material he said resembled “Rubberz” in sound and lyrical patterns. WIRED’s reporter separately tried similar prompts and reported getting comparable sounds and structures.
Fenix Flexin has posted clips he described as project files from the song’s recording sessions. Medasin argued, in a since-expired Instagram Story reported by The Verge and Stereogum, that a stem-separation tool could split a completed AI-generated track into pieces that resemble session stems. That contention has not independently resolved the question of what the clips show.
Fenix told Channel 5 that he freestyled the lyrics, WIRED reported. In a response to commenters on an On the Radar performance, he said the track was recorded the way he makes his other music, with auto-tune, reverb, and what he called a “fake uk accent.”
What can Treblo’s detector actually prove?
A detector result is evidence about the audio, not proof of authorship, intent, or every production step. Treblo says its classifier is specific to its model. Its reported false-positive rate also needs caution: The Verge cited a company claim of fewer than one false positive per 1,000 tests, while Stereogum reported Treblo’s claim as fewer than one in 10,000. Neither figure is independently validated in the reporting available.
“Rubberz” reached No. 58 on the Billboard Hot 100, according to WIRED and Stereogum. Tremblay told The Verge it could be the first known AI-generated track to reach the chart. That remains contingent on the underlying, disputed conclusion about how the song was made.
This story draws on original reporting from The Verge.
