beat-sync-editing

Beat-Sync Editing (Cuts & Rhythm)

The timeline craft: how clips and beats assemble into a piece that feels right. Editing is temporal design — when a cut lands matters as much as what is on screen. This skill turns musical and narrative structure into concrete cut points, transitions, and retimes, expressible in an NLE or as frame numbers in code.

When to use

• Assembling a sequence or cutting footage to a music track.
• Pacing drags or feels choppy; transitions feel arbitrary.
• Building speed ramps, match cuts, or tension/release structure.
• Converting an edit plan into a frame-accurate timeline (Remotion, AE, NLE).

Decision tree

What's the editing problem?
├─ Cuts feel off the music
│   └─ get BPM + offset → frames_per_beat = (60/BPM)*fps
│      → cut on PHRASES (2/4/8 beats), biggest visual on the drop
├─ A cut feels jarring / visible
│   └─ cut on action (mid-motion), match direction + velocity
│      → still rough? motivate a transition (match / J / L), else hard cut
├─ Pacing drags or feels flat
│   └─ shape an arc: Establish → Develop → Climax → Resolve
│      → shorten avg shot length toward climax, hold after it
├─ A hit needs impact
│   └─ speed ramp INTO it (slow-mo), snap back; land slowest frame on the beat
└─ Need to hand it to code
    └─ express every cut as a frame number, clip as from/duration,
       transition as overlap, retime as eased time-remap (Remotion/AE)

Cross-reference — apply the shared frameworks.

• Motion Personality (motion-art-direction) sets cut rhythm: the chosen energy maps straight to phrase length and transition family. Pick one and commit (see the table below).
• Three Pillars + beat-sync (animation-principles): settle emotional intent first (hype vs. calm) — it decides whether you cut every bar or hold for four. animation-principles defines the BPM→beat relationship; this skill turns it into frame-accurate cut points and the transition/retime craft on top.

Motion Personality → cut rhythm