---
url: https://superduperai.co/library/beat-sync-cut-not-every-beat/
title: Beat-sync cutting: cut on the beat, not on every beat
description: A rule and an agent prompt for cutting to music from a list of beat timestamps: cuts land on beats, phrases get room to breathe, and the best shot is held through the hook.
category: music
platforms: [tiktok, reels, shorts, youtube]
works_with: [claude-code, claude, chatgpt, any-llm, capcut]
tags: [beat-sync, editing, music, agent, cut-list, rhythm]
difficulty: intermediate
verified: false
created: 2026-11-01
skill: video-edit
---

# Beat-sync cutting: cut on the beat, not on every beat

A rule and an agent prompt for cutting to music from a list of beat timestamps: cuts land on beats, phrases get room to breathe, and the best shot is held through the hook.

## Prompt

```text
You are the editor. Below are the beat timestamps of the track (seconds, one per line) and the list of shots with their durations. Build an edit decision list.

Rules:
- Every cut lands on a beat. Not every beat gets a cut.
- Default rhythm: one cut every {bars_per_cut} bars (a bar is {beats_per_bar} beats). Vary it: hold a strong shot for 2 bars, then cut twice in one bar, then hold again. Three cuts at the same interval in a row is the maximum.
- Let a phrase breathe: no cut inside the last beat before a downbeat that starts a new phrase; the cut lands on that downbeat.
- The hook of the track at {hook_start} seconds gets the best shot, held, with the cut landing exactly on its first downbeat.
- A shot shorter than one beat is only allowed in a run of 3-4 (a flash sequence), once in the video.
- A score written to this cut works the other way round: its chord changes land on the beat nearest a picture cut.

Output: a table with shot id, in point, out point, which beat index the cut lands on, and a one-word reason (hold / hit / breathe / flash). Then the total duration.

Beats:
{beat_timestamps}

Shots:
{shot_list}
```

## Steps

1. Get beat timestamps first: `npm i life2film-engine` (WASM, on-device) returns beats, shots and frame scores; any beat tracker that writes seconds works.
2. Paste beats and shots into the prompt; feed the table to your editor or to the render script as the cut list.
3. Watch it once with the sound off: if the cuts still feel regular, the rhythm is too even. Merge two short shots into one hold.

## Tips

- A cut on every beat reads as a slideshow; the eye stops seeing the beat and starts seeing the clock.
- Snap to the downbeat, not to the nearest transient; hi-hats are beats too, and an agent will happily cut on them.
- In Claude Code, `/video-edit` writes the cut as a small JSON script and renders from it, so 'move that cut one beat later' is a one-line edit.

## Works with

- Claude Code: Runs as a skill or a prompt in the terminal; can read your files and write the result.
- Claude: Paste into claude.ai or the Claude app.
- ChatGPT: Paste into ChatGPT; works with any GPT model.
- Any LLM: Model-agnostic: Gemini, Mistral, a local model.
- CapCut / any editor: A manual recipe for any editor.