Fenix Flexin’s freestyle “Rubberz” rapidly climbed to #58 on the Billboard Hot 100 after its debut in June. But many listeners immediately noted that something seemed off, leading to rampant allegations that the song is AI-generated. But the LA-based rapper denies all of it.

Critics on social media pointed out that the track’s vocals didn’t really sound like Fenix, both in terms of his vocal quality and his range. For one thing, he’s singing in a strange British accent; for another, the song is an ‘80s-esque synth-pop affair, which is a genre he’s never attempted.

Then Timbaland stepped in to defend Fenix, which actually backfired and further fueled suspicions of the song’s AI roots. Timbaland, being one of the biggest AI supporters in the music industry, isn’t doing himself any favors in this instance.

Producer Medasin posted a detailed analysis of the song and why he believes it was AI-generated. One damning detail is that Fenix apparently posted a snippet of the track before it was finished, which contained “Sonauto” in the filename. Sonauto was the name of an AI music generation software that rebranded to Treblo only two days before Fenix released his song.

“You can also just use your ears,” notes Futurism’s Frank Landymore, pointing out oddities mentioned in The Verge’s own analysis of the track, including “numerous artifacts and anomalies” commonly found in AI-generated music. The vocals in the chorus sound like a “low-bitrate MP3, and reverb tails haphazardly cut off,” while other aspects contain a “certain brittle quality.”

After Medasin posted his breakdown of the song, Fenix shared a video of him going through a Pro Tools project with different aspects of the song isolated in stems, apparently to try to prove that he’d handcrafted the song. But Medasin—and numerous others—responded by noting that he could have easily just dropped the AI song into a stem splitter to achieve the same effect. Shortly afterward, Fenix deleted the video.

Meanwhile, Treblo has been enjoying the free publicity—and even released a new Treblo-specific AI-detection tool, “Was This Made With Treblo?”, over the weekend. This tool, which notably has a “microscopic likelihood” of false positives, predicts that “Rubberz” is “very likely Treblo” in origin.

“Someone appears to have used our model to find a sound that millions of people connected with, and that’s exciting,” said Treblo co-founder Ryan Tremblay.

Just a few days ago, the stacked coalition — which includes Believe, BMG, Concord, Dirty Hit, Glassnote Records, HYBE Corp., Mom+Pop Music, Partisan Records, Sony Music, Universal Music Group, and Warner Music Group — issued a joint proposal establishing unified principles to govern the eligibility of recordings developed using generative artificial intelligence in official music charts worldwide.

Just days later, the IFPI issued a set of three guiding principles for determining the chart eligibility of AI-generated (or AI-assisted) tracks.

All of which sets up a perfect test case with Fenix Flexin. So what say the newly-formed charting coalition on this matter?

Stay tuned.