The Hallway Track
Engineering Insights

Scrimshaw Jukebox

Simon Willison · Oct 06, 2026 · Engineering Insights

Claude Opus 5.5 composed surprisingly competent retro game music via a custom text format

“I wonder if the ability to compose competent music is similar to the 3D graphics thing - a new capability for text models that emerged in the past few months?”

Simon Willison prompted Claude Opus 5.5 to design a text-based music format and build a browser-playable artifact, resulting in a polished retro game music player with six original tracks. The quality was unexpectedly high, leading Willison to speculate that music composition may be an emergent capability in recent text models, analogous to 3D graphics generation. The observation is anecdotal and unconfirmed across models, but flags a potentially notable capability shift worth watching.

claude music-generation emergent-capabilities generative-ai vibe-coding

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