A Billboard hit raises red flags: Is Fenix Flexin's "Rubberz" actually AI-generated?

Fenix Flexin, part of the LA rap collective Shoreline Mafia, has struck unexpected chart success with "Rubberz," a single that reached number 58 on the Billboard Hot 100. The track arrived with immediate skepticism attached, as listeners began questioning whether generative AI tools had played a significant role in its creation. Though Fenix has rejected these claims, he has offered little concrete evidence to counter them.

A dramatic stylistic pivot#

The suspicion partly stems from the track's stark departure from Fenix's established sound. His previous work centered on trap-influenced West Coast rap, but "Rubberz" trades that foundation for '80s synth-pop aesthetics—complete with Morrissey-inspired melodies and an affected British accent. Musical reinvention is hardly uncommon, and artists experimenting with new styles should raise no automatic red flags.

Technical clues in the mix#

More troubling are the technical details hidden within the recording itself. Close listening reveals production anomalies frequently associated with AI music: brittle hi-hats, chorus vocals that resemble compressed MP3s, and reverb that cuts off unnaturally. Songwriter Charlie Harding, co-host of the Switched on Pop podcast, identified what he calls the smoking gun—"ghostly backing vocals that duck in and out without apparent reason" and drums swimming in digital artifacts "reminiscent of a 64kbps MP3 downloaded off Napster." He notes that generative AI companies often train on low-quality bootleg MP3s, audibly degrading the final output.

Running the song through five separate AI music detectors yielded ambiguous results: each flagged between 20 and 30 percent likelihood of AI involvement, though such tools remain imprecise and lag behind music-generation models themselves.

Damaging supporting evidence#

The supporting materials painted a clearer picture. The single's cover art and an Instagram post celebrating its chart success both triggered AI image detectors at over 97 percent confidence. The lyrics, fed through multiple writing detectors and large language models, also raised flags. The words exhibit the logical incoherence typical of AI output—simple rhyme schemes in an AA, BB pattern that prioritize sound over meaning.

Examining the lyrical content reveals nothing resembling a coherent narrative. One verse mentions "sinking ships" without clarification of who or what is sinking. The chorus stacks "bankrolls," "local cable," and "able" without explaining what ability is being celebrated or why. Harding observes that "no half-competent rapper would ever sing the title line in such an awkward manner," with unnatural syncopation that emphasizes the wrong syllables throughout.