Claude's new system prompt doesn't want to reproduce song lyrics

What happened

Anthropic has updated the system prompt for its Claude large language models, introducing explicit guidelines that instruct the artificial intelligence to refuse user requests for reproducing full song lyrics. This update, which was detailed in an analysis by Simon Willison on September 2, 2026, represents a clear shift in how the model handles copyrighted text and creative works during interactive chat sessions.

How it works

This article examines the mechanics of Claude's updated system instructions

Why it matters

Try it for free Claude’s new system prompt really doesn’t want to reproduce song lyrics 2nd September 2026 Anthropic publish the system prompts for their Claude consumer applications (Claude.ai and the Claude mobile apps—sadly not for Claude Cowork or Claude Code). I love that they do this, and that they share not just the current prompts but historic changes to their prompts as well.

Who is affected

A neat thing about Anthropic’s platform.claude.com/docs site is that it’s designed to be usable by LLMs. You can add .md to any page to get back the content as Markdown—here’s the system prompt index page and the Markdown prompts for Fable 5.1.

What to watch next

Once Claude has declined such a request in a conversation, it keeps declining narrower or reworded versions of it for the rest of that conversation, and offers to describe or analyze the work instead. See the full write-up from HN Claude/Codex/Fable via the source link for quotes and complete context.