song-analysis

song-analysis is a skill for Claude Code, Codex from PerIPan/music-workflow-skills. It costs 55 tokens per session (4,376 once invoked), scanned A, original, MIT.

A toolkit for examining recorded songs and turning their musical details into useful data, such as tempo, key, chords, separate instrument tracks, MIDI notes, and timed lyrics.

In plain words
What is it for?
It helps create chord-and-lyric charts, transcribe bass or drum parts, separate stems (individual instrument tracks), and measure timing.
Why use it?
It reduces the manual work involved in figuring out how a song is structured and played from an audio recording.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It helps create chord-and-lyric charts, transcribe bass or drum parts, separate stems (individual instrument tracks), and measure timing.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/peripan/music-workflow-skills/song-analysis
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add PerIPan/music-workflow-skills --skill song-analysis
Clone the repo
git clone --depth 1 https://github.com/PerIPan/music-workflow-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for song-analysis

README.md
[![agentmods](https://agentmods.dev/badge/skills/peripan/music-workflow-skills/song-analysis/github.svg)](https://agentmods.dev/skills/peripan/music-workflow-skills/song-analysis)
Your own site
<a href="https://agentmods.dev/skills/peripan/music-workflow-skills/song-analysis"><img src="https://agentmods.dev/badge/skills/peripan/music-workflow-skills/song-analysis/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for song-analysis

Your own site · 80×15
<a href="https://agentmods.dev/skills/peripan/music-workflow-skills/song-analysis"><img src="https://agentmods.dev/badge/skills/peripan/music-workflow-skills/song-analysis.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,376 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00055 $0.04376
Opus 5.5 $0.00022 $0.01750
Sonnet 5.5 $0.00011 $0.00875
Haiku 4.5 $0.00006 $0.00438

Measured 1mo ago against content hash c7c40ef108b4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

song-analysis scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

The scan reads SKILL.md. This mod also ships 15 executable files (bench/run_bench.py, scripts/align_lyrics.py, scripts/bass_notes.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

song-analysis/SKILL.md · 286 lines

How it starts

The opening of the file, as written. The whole thing — 286 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Song Analysis — recording → bars, chords, lyrics, chart

Song-agnostic pipeline, validated over many real projects (dream pop, Greek laiko, punk reinterpretations, drone/devotional). Works for any song, genre, key or meter.

References (read on demand):

  • references/meter-detection.md — how the meter sweep works, reading its output, calibration
  • references/stems.md — separation options, speeds, cache, quality checks
  • references/chord-proposal.md — chord benchmark, the triad cross-check, the major-bias trap
  • references/chart-and-lyrics.md — chart structure, the lyric-placement rules, HTML output
  • references/drum-pattern-analysis.md — kick/snare pattern reading; optional ADTOF
  • references/modal-theory.md — the 7 modes and the mode test, power chords, Byzantine ≠ Phrygian
  • references/lead-and-keys-extraction.md — isolated guitar/piano lines via htdemucs_6s
  • references/environment-setup.md — venvs, pinned versions, folder layout, this machine

Inputs

  1. Audio file — mp3/wav of the song (full mix).
  2. Lyrics — canonical text from an official source. Section labels (Verse, Chorus, Bridge…) come from this, not from the analyzer.

Tool per step

Phase Tool Output
1 Pulse + key scripts/foundation.py pulse (madmom beats + CNN key) foundation.json (step 1)
2 Stems demucs htdemucs_ft -d mps stems/htdemucs_ft/<song>/
3 Meter scripts/detect_meter.py → scripts/foundation.py meter meter.json, foundation.json (step 2)
4 Bass, tonic, mode scripts/bass_notes.py (pyin) → scripts/mode_test.py bass.mid, bass_per_cell.json, mode.json
5 Lyrics scripts/whisper_gated.py (gated by the vocal stem; stem and mix) lyrics.json, lyrics_mix.json
6 Sections scripts/align_lyrics.py (canonical lyrics ↔ word times) lyrics_aligned.json, sections.json
7 Chords scripts/lv_chords.py, cross-checked by scripts/chord_proposal.py chords_lv.json, chord_proposal.json
8 Chart Python → self-contained HTML chart

Read the full file on GitHub · 286 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 1mo ago Changed · -68 lines · -23 tokens per session c7c40ef108b4
  2. 1mo ago Changed · -1 lines 9fee1819d291
  3. 2mo ago First seen · 355 lines · 78 tokens per session scan A 53398bc143da

Subscribe to this mod's changes

song-analysis is a skill published in the GitHub repository PerIPan/music-workflow-skills (3 stars, last pushed 1mo ago), licensed MIT. It adds 55 tokens to every session and 4,376 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Related

song-analysis compared with skills from other repositories

song-analysis next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
song-analysisPerIPan/music-workflow-skillsSkill31mo agoMITA55Claude Code, Codex
imaging-data-commonsK-Dense-AI/scientific-agent-skillsSkill56k4d agoMITA73Claude Code, Codex
lab-hardware-cadK-Dense-AI/scientific-agent-skillsSkill56k4d agoMITA108Claude Code
statistical-analysisK-Dense-AI/scientific-agent-skillsSkill56k4d agoMITA111Claude Code, Codex
biopythonK-Dense-AI/scientific-agent-skillsSkill56k4d agoMITA65Claude Code
neuropixels-analysisK-Dense-AI/scientific-agent-skillsSkill56k4d agoMITA99Claude Code, Codex
onekgpdK-Dense-AI/scientific-agent-skillsSkill56k4d agoMITA143Claude Code