Sony Music has moved to dramatically expand its copyright lawsuit against AI music generator Udio, seeking to add 30,442 copyrighted sound recordings to the case. The motion, filed on May 22 in US federal court, represents one of the largest single additions of claimed works in any AI copyright case to date and signals an escalation in the music industry's legal campaign against generative AI platforms.
The expansion comes nearly two years after Sony first filed suit against Udio, alleging that the AI company trained its music generation models on copyrighted recordings without permission. The additional works were identified after Sony gained access to Udio's training data during the discovery process, using audio recognition technology from Audible Magic to match copyrighted recordings within the training dataset.
"Plaintiffs identified hundreds of thousands of audio files in Udio's training data that match copyrighted recordings," Sony's legal team stated in the filing. "The 30,442 works identified in this amended complaint represent those for which Sony Music has confirmed ownership, registration, and rights."
Udio Fights Back
Udio has opposed the proposed amendment, arguing that the massive expansion would fundamentally alter the scope of the case and delay proceedings by months. The company's attorneys contended that Sony cannot simply add tens of thousands of works without meeting legal requirements for each individual claim, including proof of ownership, copyright registration, and validity.
"Allowing this amendment would transform a focused copyright dispute into an unmanageable administrative exercise," Udio's opposition brief stated. "Each of the 30,442 additional works would require individual analysis of ownership, registration status, and alleged infringement."
The dispute is scheduled for discussion at a status conference on July 10, where the court will consider both the proposed amendments and issues related to Udio's fair use defense.
The Fair Use Question
At the heart of the case is a question that could define the legal framework for AI music generation: does training an AI model on copyrighted recordings constitute fair use? Udio has maintained that its use of copyrighted material is transformative and that the outputs of its model are new creative works, not copies of existing recordings.
In a notable admission during the discovery process, Udio acknowledged that it had scraped YouTube audio to build portions of its training dataset -- a practice that potentially violates both YouTube's terms of service and copyright law, depending on how courts interpret fair use in the context of AI training.
Sony's strategy of identifying specific works in the training data is designed to undermine the fair use argument by demonstrating the scale and directness of the copying. If the court allows the amended complaint, Sony would be able to claim statutory damages of up to $150,000 per work for willful infringement -- a potential exposure that could exceed $4.5 billion for the 30,442 works alone.
The Broader Legal Landscape
The Sony-Udio case is part of a larger wave of AI copyright litigation. A parallel case brought by Sony, Universal, and Warner against AI music startup Suno has also expanded, with damages potentially topping $9 billion after the labels added another 61,026 tracks to their claims.
These cases will likely set precedents that extend well beyond the music industry. The legal principles established in AI music training disputes will inform how courts evaluate AI training practices across all creative domains -- from visual art to written text to software code.
What to Watch
The July 10 status conference will be a pivotal moment. If the court permits the expanded complaint, it will signal that rights holders can use the discovery process to dramatically increase the scope and financial stakes of AI training lawsuits. If denied, Udio and other AI companies may find breathing room to pursue their fair use arguments on narrower grounds.
"Allowing this amendment would transform a focused copyright dispute into an unmanageable administrative exercise."— Udio Legal Team, Defense Counsel, Udio