An AI Music App's Own Detector Is Now Flagging Two Rappers' Songs as AI-Generated

Key points

• Fenix Flexin's "Rubberz," which reached number 58 on the Billboard Hot 100 in summer 2025, has been flagged as "Very likely Treblo" by an AI music detection tool.
• Treblo, a generative AI music app, meaning software that can compose full songs from a text prompt, built and published its own detector after independent producers accused two artists of using it.
• Rapper Tyga's track from his $TARFACE project returned a result of "Likely Treblo" when run through the same tool.
• Treblo's cofounder confirmed the company had no contact with either artist and was unaware "Rubberz" existed until it appeared on the Billboard chart.
• Treblo says its detector produces fewer than one false positive in every ten thousand tests, though that figure has not been independently verified.

Sometimes the most damning witness is the tool itself.

Fenix Flexin spent the summer insisting his hit track "Rubberz" was recorded the old-fashioned way. His producer denied it too. No mainstream AI detection service flagged the song. For months, fans arguing about whether the track was AI-generated had nothing solid to go on.

Then Treblo, the little-known AI music app that independent producers were already pointing at, published its own detection page last Sunday night. Feed a song into it and the tool tells you whether it was made with Treblo's software. "Rubberz" came back "Very likely Treblo." A track from Tyga's recent $TARFACE project came back "Likely Treblo."

How did this start?

Suspicion about "Rubberz" began the day it dropped on 5 June. The song is a synth-pop track in the style of moody 1980s pop, a sharp left turn for an artist known for gritty Los Angeles rap. The voice on it sounds nothing like Fenix Flexin's recognised nasal delivery. He told a Channel 5 interviewer he had freestyled the lyrics and was simply using a fake British accent with heavy reverb.

The case against him sharpened last Thursday when a music producer named Medasin posted a video laying out his theory step by step. He pointed to an Instagram Story Fenix had posted teasing new music. Freeze the frame and zoom in: the file shown on screen carries the suffix "Sonauto.mp3." Sonauto was the previous name of Treblo, changed two days before "Rubberz" came out.

Medasin went further. He opened Treblo, typed in tags like "80s synthwave" and asked it to write lyrics about a rapper's lifestyle. The song he got back shares multiple phrases with "Rubberz": both have lines about heavy diamond chains, faces seen in glass or champagne bubbles, and the phrase "pockets thick." His own attempt produced the couplet "Rings on every finger / Leather seats and cedar scent linger," a close match to "Rubberz"'s "Gold rings on my fingers / Still your perfume lingers."

Does the detector prove anything?

Not conclusively, but it is hard to dismiss. Treblo says its tool is tuned specifically to catch songs made with its own software with little or no editing, and it claims a false-positive rate below one in ten thousand. The company has released the underlying code as open-source software, meaning anyone can inspect and test it freely.

Treblo cofounder Ryan Tremblay told Wired AI the company had no prior contact with either artist. "Someone appears to have used our model to find a sound that millions of people connected with," he said, "and that's exciting."

Fenix posted what he said was the original studio project file for "Rubberz" on Instagram after Medasin's first video, but deleted it within hours. Producers who commented before it came down said the file looked like a full song broken apart using a "stem separator," software that splits an existing track into its basic parts, which would not prove the song was human-made. Neither Fenix nor his producer has responded to requests for comment.

What should listeners watch for?

This story is about more than one summer track. AI music tools are now good enough that even fans of an artist may not recognise when a voice has been replaced or heavily altered. A few things worth keeping in mind:

• If a song sounds dramatically different from everything an artist has released before, that is worth noting.
• File names and metadata in shared screen recordings can accidentally reveal the software used.
• AI detectors are useful but not perfect. A clean result does not guarantee a song is human-made, and a flagged result is not a conviction.
• The artist or label denying AI use is not evidence either way. Ask whether they have shown verifiable proof.

The detector code is public. Researchers and journalists can now test it themselves, which is the fastest route to knowing whether Treblo's one-in-ten-thousand claim holds up.