# Animate a full music video to the beat with an agent-written engine

> A creator had Opus 5.5 write a 22,000-line Python engine that times every one of 4,320 frames to a song, getting exact beat sync for about $187 in total AI costs after a video model kept landing seconds late.

- URL: https://paperchasewebb.ai/bots/marketplace/items/animate-a-full-music-video-to-the-beat-with-an-agent-written-engine/
- Type: Agent use case pack
- Category: Creative and video
- By: PaperChaseWebb
- Works with: Claude (named in the listing); Plain .md
- Price: Free USD
- Difficulty: Advanced
- Setup time: 1 hr
- Time to result: One working session
- Format: Markdown (.md) file, animate-a-full-music-video-to-the-beat-with-an-agent-written-engine.md
- Version: 1.0, updated 2026-10-26
- License: Personal and commercial use. Credit the original source when you share the workflow.

## What you end up with

The author tested a video model with the song as input and it came in 1.25 to 2 seconds late each time, with a projected cost near $480 for the full piece, against $0.30 for the code-timed version of the same test clip.

## What you get

- A plain-language summary of the workflow
- A fill-in prompt template
- What to watch out for
- A link to the original source

## Who it is for

Builders who already use AI agents and want a proven workflow they can copy into their own project.

## Tools needed

- Claude Opus 5.5: wrote the Python engine over about a week
- Suno: made the song
- Stem splitting, beat tracking and forced alignment: turn the song into a timing map
- Wan image-to-video: source clips that were sliced into 1,933 single poses
- You need: An AI coding agent or chat model
- You need: A small real task to try it on

Cost to run: Free with the agent plan you already use.

## How it works

1. **Read what they did.** Skim the source post linked below, then the summary on this page. Expected: You know the setup and the one rule that made it work.
2. **Fill in the template.** Copy the prompt and replace every [bracketed] value with your own project details. Expected: A prompt that fits your project.
3. **Run it once and check.** Run it on a small task first and confirm the result yourself before you trust it on real work. Expected: One verified run.

## Sample prompt: Workflow template (Claude Opus 5.5, Suno)

```
Split the song into stems and build a beat and word timing map
Write choreography as code pinned to bar numbers and timestamps
Let a physics step fill motion between the pinned moments
Build a pose library from generated clips and swap poses on a fixed note length
Render, review and repeat
```

Adapted by PaperChaseWebb. Not the original author's prompt.

## Free preview of animate-a-full-music-video-to-the-beat-with-an-agent-written-engine.md

````markdown
# Animate a full music video to the beat with an agent-written engine

PaperChase agent use case (free feed entry), version 1.0. Source: [u/chrisBhappy on r/ClaudeAI](https://www.reddit.com/r/ClaudeAI/comments/1xdnfqe/opus_55_animated_this_music_video_frame_by_frame/), 2026-10-23.

## What they did

The engine first breaks the song down: separate vocals, drums and bass, map the tempo, and timestamp each sung word. Choreography is written as code pinned to exact moments in the song, and a simple physics solver fills in runs and jumps between those points. The runner is drawn from a library of hand-picked poses, each held for roughly two frames, which gives a stop-motion look. The result is one continuous shot with camera motion, paint and rain effects.

## Worth knowing

The author tested a video model with the song as input and it came in 1.25 to 2 seconds late each time, with a projected cost near $480 for the full piece, against $0.30 for the code-timed version of the same test clip. It took 12 full renders. This is a big build, but the core idea (put timing in code, use generated images only as a pose library) works at small scale too.
````

## Worth knowing

- The author tested a video model with the song as input and it came in 1.25 to 2 seconds late each time, with a projected cost near $480 for the full piece, against $0.30 for the code-timed version of the same test clip. It took 12 full renders. This is a big build, but the core idea (put timing in code, use generated images only as a pose library) works at small scale too.
- Figures are as reported by the original author and were not re-measured by us.

## Questions

**Where does this come from?** A public post credited to u/chrisBhappy on r/ClaudeAI. Source: https://www.reddit.com/r/ClaudeAI/comments/1xdnfqe/opus_55_animated_this_music_video_frame_by_frame/

**Is it free?** Yes. Feed entries are free to read and download.

## How to get it

Free sample. Download it directly at https://paperchasewebb.ai/bots/marketplace/items/animate-a-full-music-video-to-the-beat-with-an-agent-written-engine/, no signup.

Seller: PaperChaseWebb Inc., mgmt@paperchasewebb.com