Music publishers Universal Music Publishing Group, Concord and ABKCO filed a motion for partial summary judgment against Anthropic on March 23, 2026, in federal court in Northern California. They want the judge to decide, without a full trial, that the company infringed their copyrights and that its fair use defence fails. The case dates from October 2023 and concerns 499 songs. Summary judgment is only granted when the key facts are not genuinely in dispute, and the publishers argue Anthropic's own admissions leave nothing material to contest on infringement or fair use.
The filing comes with a 47-page statement listing 218 facts the publishers say are undisputed, drawn from depositions, internal documents and Anthropic's own admissions. Among them, according to the motion, is an admission that at least one Claude model was trained on data containing the lyrics to at least 100 of the works, and that Anthropic never sought a licence. In a statement to MBW the publishers called the infringement massive and the evidence "overwhelming".
On fair use, they argue the copying was commercial, involved whole lyrics, and produced output that competes with licensed lyric services such as LyricFind and Musixmatch. They point to a sworn statement by chief science officer Jared Kaplan that the company has no particular interest in their songs and treats such works as interchangeable for training, and argue this undercuts any claim that the lyrics were needed for transformative uses. They also cite Deezer's figures on AI tracks flooding streaming services as evidence of market harm, and argue that when Claude hands users lyrics it is doing what their licensees do, without permission or limits.
The motion describes how the lyrics were allegedly gathered, by scraping the web and datasets such as Common Crawl and The Pile, and says Anthropic's records show Claude returning lyrics for translation, chord, homework and songwriting requests, sometimes when users had not asked for them. It also points to a public fine-tuning dataset on Hugging Face containing prompts that ask for lyrics to songs in the suit. It quotes an internal 2023 memo saying models memorise a great deal, cites testimony from co-founder Benjamin Mann and CEO Dario Amodei on memorisation and verbatim output, and says reviewers building a fine-tuning dataset favoured accurate lyric outputs. It adds that guardrails introduced after the suit did not stop every reproduction, listing songs such as American Girl, Dog Days Are Over and White Christmas.
This is separate from the publishers' second suit, filed in January 2026, which covers more than 20,000 songs and seeks over $3 billion. BMG filed its own lawsuit against Anthropic the week before this motion. Anthropic's response was not part of the report.
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