A song climbing the Billboard Hot 100 has become the centre of a much bigger argument about whether audiences can still tell when music is made by a person.
‘Rubberz’, a solo track by Shoreline Mafia rapper Fenix Flexin, has climbed to No. 58 on the US chart. The success should have marked a major solo breakthrough. Instead, the conversation around the song has been dominated by claims that its vocals, instrumental and possibly its lyrics were created with generative AI.
Fenix has denied the accusation. Producers and music commentators remain unconvinced. Nobody outside the people who made the recording has released evidence that settles the matter completely, leaving ‘Rubberz’ as one of the clearest examples yet of the trust problem now facing the music industry.
A Sudden Change in Sound
Fenix Flexin is best known for West Coast rap as one half of the current Shoreline Mafia line-up. ‘Rubberz’ sounds almost nothing like the style listeners associate with him.
The track leans into 1980s British synth-pop, with glossy keyboards, electronic drums and a deliberately exaggerated English accent. The vocal melody has also drawn comparisons with the melancholy style associated with The Smiths.
A dramatic reinvention is not proof of AI. Artists change genres, adopt characters and use studio effects all the time. Pitchfork’s early review treated the song as an eccentric but genuine experiment, noting that Fenix had discussed trying different genres and had spoken publicly about preparing the accent.
The problem is that the stylistic change is only one part of the suspicion.
Why Listeners Think It Sounds Artificial
The Verge examined the finished recording with songwriter and ‘Switched on Pop’ co-host Charlie Harding. He pointed to several production details that can appear in music made by generative systems, including brittle percussion, backing vocals that appear and disappear unexpectedly, degraded-sounding instrumentation and reverb that cuts off in unnatural places.
The phrasing has also attracted attention. Some lines place the emphasis on unusual syllables or squeeze words into the rhythm in ways that sound awkward for an experienced rapper. Other sections rhyme neatly without building a clear story, which has led critics to compare the writing with the plausible-sounding but disconnected lyrics produced by AI music tools.
None of these clues is conclusive. Human musicians can make unusual rhythmic choices, write deliberately absurd lyrics and release recordings with poor-quality effects. A strange song is not automatically a synthetic song.
Taken together, however, the vocal delivery, audio artefacts and disconnected writing have given the theory enough weight to survive beyond ordinary social media speculation.
AI Detectors Could Not Settle the Question
The obvious response is to run the song through an AI detector. That did not produce a clear answer.
The Verge reported that five music-detection tools placed the likelihood of AI involvement at only around 20 to 30 per cent. Those results are far too uncertain to prove that the recording was generated, but they do not prove it was entirely human either.
Detection tools have an unavoidable weakness. They are usually trained to recognise patterns left by models that already exist. A new generator, a heavily edited output or an AI track that has been separated into stems and rebuilt inside conventional production software may no longer match those patterns.
Ordinary music production can also confuse a detector. Compression, pitch correction, noise reduction, vocal layering and low-bitrate audio can create some of the same signals the software is looking for.
That means AI detection currently works better as one clue than as a verdict.
A Producer Points to Treblo
The allegations became more specific when electronic producer Medasin published a detailed breakdown arguing that ‘Rubberz’ had been generated with Treblo, an AI music platform previously known as Sonauto.
According to reporting by Stereogum, Medasin highlighted an earlier song preview posted by Fenix that appeared to include ‘Sonauto’ in the file name. He also used Treblo to produce examples with vocal qualities, genre combinations and lyrical habits that he believed resembled ‘Rubberz’.
The demonstration made the claim more credible, but it still did not reveal the original prompt, account history or source file used to make the released song. Similar output from the same tool can show that a theory is possible without proving that it is what actually happened.
Medasin’s argument is therefore important circumstantial evidence, not a verified production record.
Fenix Flexin Says the Song Is Real
Fenix has rejected the claims from the beginning. He has said the track was recorded in the same way as his other music and blamed the unusual sound on a combination of Auto-Tune, reverb, vocal processing and the deliberately adopted accent.
He has also posted clips that appeared to show ‘Rubberz’ divided into separate tracks inside Pro Tools, the recording software used in professional studios.
Those files demonstrate that the final song was assembled and edited in a normal production environment. They do not necessarily reveal where every sound began. AI-generated songs can be split into vocals, drums, bass and instrumental stems, then edited, layered with new recordings and mixed in conventional software.
Medasin argued that this was what the Pro Tools footage showed. Fenix later removed the post, which fuelled more speculation but still did not establish that the accusation was true.
Live Performances Added More Doubt
Fenix has performed and promoted the song in several live and studio settings, but those appearances have not ended the debate.
Critics have pointed to heavy reliance on the released backing vocal and moments when his untreated voice appears different from the character heard on the record. They argue that he has struggled to reproduce the recorded range, timing and accent consistently.
That evidence also has limits. Rap and pop performances regularly use backing tracks, doubled vocals and studio processing that cannot be recreated exactly on stage. A weak live performance does not prove that the original voice was generated by a machine.
It does, however, make a straightforward explanation harder when listeners are already questioning how the recording was made.
What Does ‘AI-Generated’ Actually Mean?
Part of the confusion comes from treating AI music as a simple yes-or-no category.
A complete song can be generated from a text prompt, but AI can also be used to create only an instrumental, imitate a voice, rewrite lyrics, produce an early demo, separate audio into stems, clean a recording or generate material that musicians later recreate.
Those approaches involve very different amounts of human work. A singer using AI to remove background noise is not doing the same thing as placing a name on a finished song generated from a prompt.
Without clear credits, listeners are being asked to reverse-engineer the process from sound quality, social media posts and live footage. That is an unreliable and often unfair way to judge an artist.
The Bigger Problem Is Disclosure
There is still no publicly available evidence that proves ‘Rubberz’ was entirely generated by AI. There is also enough unusual evidence to explain why the questions have not disappeared.
The strongest conclusion is not that the song has been exposed as fake. It is that the music industry is poorly prepared for recordings that sit somewhere between human performance and machine generation.
As AI music improves, audible flaws will become less useful. Project files can be rebuilt. Human vocals can be layered over synthetic material. Detectors will continue chasing generators that evolve faster than they do.
Labels, streaming services and chart organisations may eventually need consistent rules requiring artists to disclose meaningful generative AI use. Credits could identify whether AI created the voice, music or lyrics, while still allowing musicians to use less controversial assistance tools.
That would not end arguments about copyright or artistic value, but it would give audiences a clearer basis for deciding what they want to support.
Was ‘Rubberz’ Made by AI?
The evidence makes AI involvement plausible, but it does not make it proven.
The production artefacts, the disputed live performances, the possible Sonauto file name and Medasin’s Treblo demonstration all strengthen the suspicion. Fenix’s denials, public explanation and Pro Tools footage provide a competing account, even if they have not convinced his critics.
A definitive answer would require material that has not been released publicly, such as the original vocal takes, complete project history, generation records or other independently verified production files.
Until then, ‘Rubberz’ remains a chart hit with an unresolved authorship question. The fact that millions of listeners cannot confidently tell how it was made may be more important than the final answer.
Why This Matters for Australia
Australian musicians, producers and listeners will face the same problem as generative music becomes easier to release and harder to identify. A track can reach playlists, radio and local charts without audiences receiving a clear explanation of whether its voice, lyrics or instrumental came from a person, a model or a mixture of both.
APRA AMCOS has argued that AI in music must be built around consent, credit, transparency and fair payment. Its research found that 23 per cent of Australian and New Zealand music creators’ revenue could be at risk by 2028, with an estimated cumulative impact of $519 million if generative systems replace work without a workable remuneration model.
The practical response is not to label every heavily processed song as fake. Australian platforms and rights organisations need clear disclosure standards, while listeners should treat detector scores and viral accusations as clues rather than proof.
Source: The Verge
