By Mythic Media Entertainment ~ September 18th, 2026
Nine days after Suno launched v6 in partnership with Warner Music Group, BMG, and Believe, framing it as the moment AI and the music business finally move forward together, Sony Music and Universal Music Group filed a new 45-page lawsuit against the company. Their argument is not just aggressive. It is one of the more precise pieces of legal reasoning to come out of this entire fight, and it deserves credit as exactly that, whatever you think about AI music generally.
The Poisoned Tree
The core claim is straightforward once you see it. Suno has publicly admitted that v6 was trained in part on user interactions, meaning the outputs of, and preference signals derived from, its earlier models. Those earlier models are the same ones already alleged in the original 2024 suit to have been trained on unlicensed recordings, Sony and UMG's included. Sony and UMG's filing calls this exactly what it is: training a new model on the outputs of an infringing model does not eliminate the infringement, it launders it, passing the value of the original copyrighted recordings from the old models into their outputs, and from those outputs into v6.
That is not a technicality. That is a serious ethical and legal point about what training data actually is. If a model learned patterns, structures, and stylistic fingerprints from copyrighted recordings, and a later model learns from that first model's behavior, the copyrighted material's fingerprints do not disappear just because a new layer got added on top. Calling v6 a fresh start, when its own predecessor's DNA is still running through it, is the kind of claim that should have to survive real scrutiny, not just a press release.
The Move That Actually Impresses Me
Here is the sharper part. Suno's entire legal defense from day one has rested on fair use, specifically the argument that using copyrighted recordings to train a model caused no market harm, because there was no existing market for AI training data in the first place. Nobody was paying for it, so using it for free harmed no one.
Suno has now signed paid licensing deals with Warner Music Group, BMG, and Believe to build v6. Sony and UMG's filing points out the obvious consequence: a company that is now paying real money for training data has just admitted, in the clearest way possible, that a market for that data exists. You cannot argue there was no market to harm in one breath and sign checks proving the market exists in the next. Sony and UMG are not just suing over new recordings here. They are using Suno's own licensing deals as evidence that the original fair use defense never held up. That is a genuinely brilliant use of Suno's own actions against it, and it is hard to see how Suno's lawyers walk that back now that the ink is already dry.
This Isn't About Killing AI Music. It's About Who Gets to Skip the Line.
Warner already settled, signed a license, and is out of this case entirely. This suit comes from the two majors who have not yet gotten their own deal. That matters. Sony and UMG are not trying to stop AI music from existing, they are refusing to let Suno declare the fight over and move on before they get paid the same way Warner did. Suno tried to use v6's launch to write a new chapter where the lawsuits are history. Sony and UMG's response is essentially: not yet, not until we are at the table too.
There is something fair about that, even if the $9 billion theoretical number attached to it is mostly leverage rather than a real expectation. Suno built a real, useful product. It also built it on copyrighted material it did not pay for, then negotiated deals with the labels willing to settle, while implying to everyone else the matter was resolved. Sony and UMG are not wrong to say it wasn't, not for them.