SAN FRANCISCO, California: Sony Music and Warner Music's publishing arms have sued Anthropic in California federal court, alleging the AI company illegally used copyrighted song lyrics and sheet music to train its Claude models.

Sony and Warner said in a complaint filed on August 31 that Anthropic pirated hundreds of song lyrics and sheet music from The Beatles, Taylor Swift, Michael Jackson and hundreds of other artists to train Claude to respond to human prompts.

The case joins a wave of lawsuits brought against technology companies by authors, publishers, music labels and news organizations over the use of copyrighted material to train artificial intelligence systems.

Universal Music Group sued Anthropic in 2023 over the alleged use of copyrighted song lyrics in AI training. That lawsuit is still ongoing.

Anthropic became the first AI company to settle one of the disputes last year, paying US$1.5 billion to resolve a class action brought by a group of authors.

"Anthropic clearly considers that to be just the cost of doing business given that its entire business model continues to be built on copyright theft," Sony and Warner said in their complaint. "And $1.5 billion is obviously not a large enough settlement to deter infringing conduct by a company that has parlayed such mass infringement into a staggering $2-trillion-dollar valuation."

Spokespeople for Anthropic, Sony Music and Warner Music did not immediately respond to requests for comment.

The complaint alleges that Anthropic illegally obtained the publishers' lyrics and sheet music through torrent downloads to train Claude. It also alleges that Claude can reproduce copyrighted lyrics "verbatim" when prompted.

Sony and Warner said Anthropic also used their lyrics to teach Claude to "generate vast quantities of purportedly 'new' AI-generated song lyrics, which compete with Music Publishers' legitimate copyrighted works as harmful market substitutes."

The music publishers are seeking damages of up to $150,000 for each infringed copyright as well as a court order barring Anthropic from using their works.