Sony and UMG are suing Suno again over its new v6 model

Sony Music and Universal Music Group are suing Suno again, arguing that the company's new v6 model does not escape the copyright problems of the models that came before it. The complaint, filed on September 18 in Boston federal court, accuses Suno of "model laundering": building v6 on outputs and preference signals from earlier models the labels say were trained on unlicensed recordings ripped from YouTube and elsewhere.

The "model laundering" claim

According to Music Business Worldwide, the filing names 60,202 recordings. US copyright law allows damages of up to $150,000 per work for willful infringement, which puts the theoretical maximum of the claim at just over $9 billion. The labels also seek up to $2,500 for each act of circumventing YouTube's anti-downloading technology, plus an injunction and a jury trial.

At the centre of the complaint is v6, launched on September 9. "Training a 'new' model on the outputs of an infringing model does not eliminate the infringement; it launders it, passing the value of Plaintiffs' expression from the copied recordings into the tainted models, from those models into their outputs, and from those outputs into v6," the labels wrote in the complaint shared with The Verge. "V6 is not a fresh start; it is the fruit of the same poisoned tree."

Sony also alleges that Suno used knowledge distillation, training v6 to replicate the results of earlier, "teacher" models that were themselves built on infringing data. It argues that "even a model not directly trained on Plaintiffs' recordings is informed by, and benefits from, Suno's retained unauthorized copies."

What Suno says

Suno has said v6 was built on licensed material. Chief product officer Jack Brody told The Verge the model was "trained from the ground up, with a new set of data," including "user data," but gave no further detail. Suno later confirmed to Engadget that the data includes "creations" from users, without elaborating further. The labels counter that those user interactions are themselves outputs of earlier Suno models: Suno generates two tracks per prompt, and the record of which one a user picks is the preference data that shaped v6.

Why it matters

It is the second time the two labels have taken Suno to court. Sony and Universal sued the company in June 2024, together with Warner Music Group, over unlicensed training. Warner settled in November 2025 and signed a licensing partnership with Suno, and BMG and Believe later did the same. UMG and Sony stayed out, so the dispute now turns on whether a model trained with licensed partners can still count as clean if it learned from predecessors built on other catalogues.