Imported from CertifiedWebMaster/RoofGrid (external/video-editor/.claude/skills/add-music/SKILL.md). Install upstream with npx skills add CertifiedWebMaster/RoofGrid --skill add-music. Copyright stays with the author.

Add background music

Name: add-music
Author: CertifiedWebMaster

Stage 6 of the 7-stage pipeline. Input: the rendered video (graphics + captions already applied) and a music file. Output: same video with the music mixed under the existing dialogue track — dialogue level is untouched.

Steps

python3 scripts/add_music.py <path to edited video> <path to music file> \
  --db -23 \
  --out projects/<slug>/final-with-music.mp4

--db is the music level in dB relative to 0 (full scale), NOT a volume percentage. More negative = quieter. Start at -23 for "barely there" background music under spoken dialogue; ask the user to A/B a couple of values (-18 vs -23 vs -28) rather than guessing one number is right.
The track loops if shorter than the video and trims if longer — the output always matches the video's duration exactly.
Drop reusable tracks into assets/music/ so future projects can reference them by a short path instead of a full Downloads/Desktop path.

After this stage

Move to export (export-video skill) once the mix sounds right.

{ "ocm": "1", "id": "certifiedwebmaster-roofgrid-add-music", "kind": "skill", "name": "add-music", "description": "Mix a background music track under an already-edited video at a chosen loudness. Use when the user wants to add background music / a song under their finished (or nearly-finished) edit. Not for beat-synced music videos where the song drives the cuts (use the HyperFrames music-to-video skill for that).", "publisher": "CertifiedWebMaster", "version": "1.0.0", "capabilities": { "domains": [ "creative" ], "tags": [ "skill-md", "github" ], "languages": [ "en" ] }, "quality_prior": 0.6, "examples": [ "Mix a background music track under an already-edited video at a chosen loudness. Use when the user wants to add background music / a song under their finished (or nearly-finished) edit. Not for beat-synced music videos where the song drives the cuts (use the HyperFrames music-to-video skill for that)." ], "primary": false, "metadata": { "source": { "provider": "github", "repository": "https://github.com/CertifiedWebMaster/RoofGrid", "path": "external/video-editor/.claude/skills/add-music/SKILL.md", "ref": "c67477fd5a41a8d18b50358820a495874c7be648", "url": "https://github.com/CertifiedWebMaster/RoofGrid/blob/c67477fd5a41a8d18b50358820a495874c7be648/external/video-editor/.claude/skills/add-music/SKILL.md", "key": "CertifiedWebMaster/RoofGrid/external/video-editor/.claude/skills/add-music/SKILL.md" } }, "instructions": "# Add background music\n\nStage 6 of the 7-stage pipeline. Input: the rendered video (graphics +\ncaptions already applied) and a music file. Output: same video with the music\nmixed under the existing dialogue track — dialogue level is untouched.\n\n## Steps\n\n```bash\npython3 scripts/add_music.py <path to edited video> <path to music file> \\\n --db -23 \\\n --out projects/<slug>/final-with-music.mp4\n```\n\n- `--db` is the music level in dB relative to 0 (full scale), NOT a volume\n percentage. More negative = quieter. Start at -23 for \"barely there\"\n background music under spoken dialogue; ask the use", "cost": { "context_tokens": 261 } }

add-music

About

Add background music

Steps

After this stage

Use it

Manifest

Reviews