Sony Music has again moved to amend its high-stakes complaint against Udio, according to filings shared over the weekend with Digital Music News. And right on cue, Udio aggressively pushed back against the request. Two years and one discovery marathon later, it was only in late April that the defendant formally answered the suit’s present version and doubled down on its longstanding fair use arguments.

The intensified litigation offers yet another indication that the ‘Big Three’ aren’t seeing eye-to-eye on gen-AI matters. Despite Udio’s settlements with Universal Music as well as Warner Music, Sony Music is clearly charging ahead with its case.

Moving beyond some unsurprising changes (like dropping the ex-plaintiffs while adding several Sony Music subsidiaries), the proposed amended complaint’s most significant element is undoubtedly the huge pile of allegedly infringed works.

And by capitalizing on “a systematic process for identifying their specific copyrighted works within Udio’s training dataset” – in brief, by leveraging Audible Magic – the Sony Music plaintiffs are said to have “identified hundreds of thousands” of allegedly infringed audio files.

“To be clear, Plaintiffs have a sufficient basis to assert claims against Udio as to all the works they own or control that returned match results within Udio’s training data. However, in the interest of ensuring the orderly progress of this litigation and facilitating swift resolution of the key issues, Plaintiffs have elected to prosecute Udio’s use and reproduction of approximately 30,304 works,” Sony Music wrote.

As noted, this definitely isn’t sitting right with Udio, which, ahead of a scheduled July 10th status conference, took aim at the retooled action “because it would effectively start discovery over from scratch with respect to tens of thousands of additional works and multiple new parties.”

Additionally, allowing the amended suit to proceed would allegedly fuel a “delay for many months” when it comes to a decision on Udio’s above-highlighted fair use claims.

“Plaintiffs’ delayed efforts to identify allegedly infringed works and amend their complaint (when they apparently felt they had a basis for asserting the current works without any discovery) cannot excuse blowing up the schedule at this late date,” Udio’s legal team proceeded.

In the bigger picture, it goes without saying that the intensifying infringement litigation isn’t a positive for the defendant – especially as it reportedly prepares to roll out a walled-garden app enabling authorized soundalike covers.

Bearing in mind Spotify’s soon-to-be-released AI tools, time will tell how many gen-AI walled gardens the music world can support at once. Klay Vision is also teeing up the debut of its core product; as the startup has deals with all three majors, including walled-garden proponents UMG and SME, the offering’s outputs will presumably remain on-platform.