# Ableton Theory Coach

> This skill should be used when the user asks to "analyze this clip", "what chords/key/scale is this", "explain the harmony", "what's the progression", "show me the voice-leading", or wants a music-theory explanation of MIDI already in Ableton Live. Reads a clip's notes and explains the harmony, scale, and voice-leading (optionally in a WebView).

- **Type:** Skill
- **Install:** `agentstack add skill-korben00-ableton-producer-skills-ableton-theory-coach`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [Korben00](https://agentstack.voostack.com/s/korben00)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [Korben00](https://github.com/Korben00)
- **Source:** https://github.com/Korben00/ableton-producer-skills/tree/master/skills/ableton-theory-coach

## Install

```sh
agentstack add skill-korben00-ableton-producer-skills-ableton-theory-coach
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Ableton Theory Coach

Read MIDI from the Set and explain the music theory behind it — detected key/scale, chord names and
functions (Roman numerals), the progression, melodic analysis, and voice-leading observations.
Educational: it teaches *why* a part works, not just what it is.

## When to use

Triggers: "analyze this clip", "what chords/key is this", "explain the harmony/progression",
"voice-leading". To generate music use the composition skills; this one *explains existing* MIDI.

## Process

1. **Use `ableton-live-runner`** for build/run/kill + scaffold.
2. **Read the target clip's notes** (`clip.notes`) and the project context (`song.rootNote`,
   `song.scaleName`, `song.scaleIntervals`).
3. **Analyze:**
   - **Pitch-class content** → infer key/scale (compare note set to major/minor/modal templates; the
     project scale is a strong prior).
   - **Chords** → group notes overlapping in time per beat/bar; identify root + quality (triad, 7th,
     9th, sus, slash) from intervals.
   - **Function** → Roman numerals relative to the key; flag cadences, secondary dominants, modal
     interchange, the turnaround.
   - **Melody** → contour, chord-tone vs non-chord-tone usage, motif/repetition, range.
   - **Voice-leading** → common tones, smooth vs leapy motion, parallel intervals.
4. **Explain clearly** — concise, leveled to the user; name the theory and say why it sounds the way
   it does (e.g. "the ♭6 over the tonic is what makes it eerie").
5. **Optionally render a WebView report** with `api.ui.showModalDialog(url, w, h, onResult, onError)` —
   it takes a **file URL, not inline HTML**: write the HTML to `environment.tempDirectory` /
   `storageDirectory` and pass its `file://` URL; the callback returns a string. Or just print the
   analysis.

## Chord-detection sketch

```ts
function chordsByBar(notes, bpb = 4) {
  const bars = {};
  for (const n of notes) { const bar = Math.floor(n.startTime / bpb); (bars[bar] ??= []).push(n.pitch % 12); }
  return Object.entries(bars).map(([bar, pcs]) => ({ bar: +bar, pcs: [...new Set(pcs)].sort((a, b) => a - b) }));
}
// match each bar's pitch-class set against interval templates {maj:[0,4,7], min:[0,3,7], m7:[0,3,7,10], ...}
// to name root + quality; then convert to a Roman numeral relative to song.rootNote.
```

## Limits

- Detection is heuristic — ambiguous sets (e.g. rootless/quartal voicings) may need the bass clue or a
  best-guess with alternatives stated.
- Reads notes only; expression/automation isn't analyzed.

See `ableton-reharmonize`, `ableton-topline`, `ableton-describe-to-midi`.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [Korben00](https://github.com/Korben00)
- **Source:** [Korben00/ableton-producer-skills](https://github.com/Korben00/ableton-producer-skills)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-korben00-ableton-producer-skills-ableton-theory-coach
- Seller: https://agentstack.voostack.com/s/korben00
- Browse the marketplace: https://agentstack.voostack.com/browse

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