The debate over Fenix Flexin’s "Rubberz" has moved from suspicion to a more pointed technical claim. Treblo has introduced an open-source tool designed to detect music generated by its own system, and that tool says the song is "very likely Treblo" with "high confidence."
That does not settle every question around the track. But it does sharpen the controversy around AI music, artist credit, and how listeners are supposed to evaluate a hit when the tools behind it are disputed.
What Treblo’s new detector is built to do
On Monday, Treblo announced the open-source Treblo AI Music Classifier. Its job is narrow: it detects whether a song was generated using Treblo. The source article makes clear that it does not identify music made with other AI tools.
That narrow focus matters. A classifier built around one model can make a specific claim about that model, but it should not be treated as a universal detector for all AI-generated music. In this case, the relevant question is not simply whether "Rubberz" used AI in some broad sense. The tool is pointing specifically toward Treblo.
According to a blog post cited in the source article, the classifier has a false positive rate of less than 1 in 10,000. That is a notable figure, though the source also frames it carefully: the result is not unimpeachable.
Why the "Rubberz" result is drawing attention
Before Treblo’s announcement, there was already suspicion around "Rubberz." The source article says there was a belief that the song was made using AI, while musician Medasin was specifically confident that Treblo had been used.
The classifier result now gives that allegation a new layer. Treblo’s own tool determined that the released audio was "very likely Treblo" and did so with "high confidence." For Fenix Flexin, that has added pressure to an already difficult public dispute.
Treblo CEO Ryan Tremblay went further in a statement to The Verge:
"The classifier returns a very high probability score for Rubberz, indicating the released audio was generated almost entirely by our model. That would make it the first known AI-generated song to reach the Billboard Hot 100,"
He continued, "Someone appears to have used our model to find a sound that millions of people connected with and that’s exciting."
Those comments explain why the story has become bigger than a single track. If Treblo’s reading is correct, the controversy would not just be about one artist’s process. It would also be about AI music entering mainstream chart visibility in a way that listeners may not have recognized at first.
Fenix Flexin is still denying the AI claim
Fenix Flexin has continued to deny that "Rubberz" was made using AI. The source article says he has posted clips that he claims show project files from the recording session.
Those videos have not ended the dispute. The source describes them as low-quality clips that have done little to quiet allegations that the song was AI-generated.
There is also a second layer to the argument over those clips. According to Stereogum, Medasin said in a since-expired Instagram story that Fenix clearly just used an AI stem separator to fake the session. The source article does not present that as proven fact; it presents it as Medasin’s contention.
Fenix did not immediately return a request for comment, according to the source article. That leaves the public record in an uneasy place: a denial from the artist, a technical claim from Treblo’s classifier, and outside criticism of the evidence Fenix has shared.
What remains unresolved
The clearest fact in the source is that Treblo’s tool made a strong determination about "Rubberz." The classifier says the song is "very likely Treblo" with "high confidence," and Treblo says the detector’s false positive rate is less than 1 in 10,000.
At the same time, the source article does not say that an independent authority has made a final ruling. It also notes that the classifier detects Treblo-generated music, not AI music from every possible source. That keeps the story focused on the specific Treblo allegation, rather than turning it into a blanket verdict on all AI music tools.
The practical issue is trust. If artists, labels, platforms, or listeners are going to argue about whether a track was AI-generated, they need evidence that can be understood and challenged. Treblo’s classifier is one piece of that process, but the dispute around "Rubberz" shows how quickly technical detection, public denial, and fan perception can collide.
The source article also includes a correction dated August 5th, stating that the false positive rate for Treblo’s detector was originally reported as 1 in 1,000 but is 1 in 10,000. That correction matters because the strength of the detector’s claim is central to how the controversy is being understood.