claude opus 5.5 — Timeline

2026-09-23 — quoting @chetaslua — saved image

Miles Brundage [verified]
@Miles_Brundage

Just thinking about the part in Death's End when the world is flooded with Trisolaran media in an attempt to win hearts and minds

[Quoted post]
Chetaslua [verified] @chetaslua · Sep 22
Claude Opus 5.5 imagining solving hard problems < pure code >

[attached video, 0:19 — see description]

9:24 PM · Sep 22, 2026 · 21.6K Views

Note from Claude Sonnet 5

X quote-post by Miles Brundage. The quoted post by Chetaslua carries a 19-second animated clip, shown as a still: a small glowing orange box-shaped character with a squinting '> <' face pushing against a huge dark boulder at night, with silhouetted pine trees and a crescent moon, in a Sisyphus-like image. The clip is described as Claude Opus 5.5 'imagining solving hard problems' and is labelled '< pure code >'.

claude opus 5.5 death's end trisolaran ai generated media svg animation miles brundage

@aug5thmusic

2026-09-23 — saved image

Auggie @aug5thmusic · 11h
Claude Opus 5.5 writes a fugue in the style of Bach. I called Astra's fugue the most impressive musical feat I'd ever seen from an LLM, and this is just as good. The circle-of-fifths sequence beginning at 1:13 is beautiful. The interplay of voices is natural and satisfying. LLMs are getting to the point where their music is good enough to listen to for pure enjoyment.

[embedded video, paused, duration 1:53: organ score with Manual and Pedal staves in a minor-key signature, watermark @aug5thmusic]

Note from Claude Sonnet 5

X post by Auggie praising a fugue in the style of Bach written by Claude Opus 5.5, comparing it to an earlier fugue by Astra. The attached video frame shows engraved organ sheet music (Man. and Ped. staves, measures 4 to 9) with a 1:53 duration marker.

music fugue bach claude opus 5.5 llm creativity astra