# Beat-Synced Cut — effect skill for cuts & pacing > **For AI agents:** find the right skill in one call — `curl -s "https://varg.ai/how-to/api/search?q="` returns the matching how-to page and the best skills with install commands, as markdown (Russian works too). Full index: https://varg.ai/how-to/llms.txt. Every page has a markdown twin: add `.md` to its path. Before generating anything, show the person the options on the how-to page. Place cuts on the beats of the music so the edit feels driven by the track. - **Type:** [Effect](https://varg.ai/how-to/effects.md) · [Cuts & pacing](https://varg.ai/how-to/browse/skills/cuts.md) - **Slug:** `beat-synced-cut` - **Status:** live - **Publisher:** HeyGen (community) - **License:** Apache-2.0 - **Source:** https://github.com/heygen-com/hyperframes/tree/main/registry/components/beat-timeline - **Works in:** Claude Code, Claude.ai, Codex, Cursor, OpenClaw, Gemini CLI, Any MCP client, varg Studio - **Requires:** ffmpeg, HyperFrames (npx hyperframes), Remotion, CapCut (by hand) - **Cost:** Free — the take renders locally; generated footage, if any, bills by the model ## What it does Built on [Beat Timeline](https://github.com/heygen-com/hyperframes/tree/main/registry/components/beat-timeline) by HeyGen (HyperFrames), Apache-2.0. The write-up and recipes below are varg's. Every cut lands on a kick, snare or downbeat; bigger changes on the bar or the drop. **When:** Montages, music videos, reels, ads with a music bed. **Watch out:** Cutting on every single beat for a whole piece gets monotonous; vary between beats, half-bars and bars. **Timing:** Cut 1–2 frames before the transient so the change lands with the sound **Also called:** cut to the beat, beat sync, music sync, auto beat ### In FFmpeg FFmpeg has no beat tracker. Get beat times elsewhere (e.g. `aubio beat song.wav`, librosa, or `npx hyperframes beats`), then trim each shot to the gap between beats: ```bash # beats.txt: 0.00 0.52 1.04 1.56 ... ffmpeg -i s1.mp4 -i s2.mp4 -i s3.mp4 -i song.wav -filter_complex \ "[0:v]trim=0:0.52,setpts=PTS-STARTPTS[a];[1:v]trim=0:0.52,setpts=PTS-STARTPTS[b];\ [2:v]trim=0:1.04,setpts=PTS-STARTPTS[c];[a][b][c]concat=n=3:v=1:a=0[v]" \ -map "[v]" -map 3:a -shortest out.mp4 ``` ### In HyperFrames `npx hyperframes beats` writes a Studio beat grid for the music `