# Tasks: enterprise-audio-analysis-pitch

**Change ID**: enterprise-audio-analysis-pitch
**Package**: `@suaveplan/audio-analysis-pitch`
**Target path**: `packages/media/audio/audio-analysis-pitch`
**Prerequisite packages on Verdaccio**: `@suaveplan/audio-core`, `@suaveplan/error`, `@suaveplan/types`

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## 1. Scaffold

- [ ] Create directory `packages/media/audio/audio-analysis-pitch/` with `src/`, `tests/`, `src/__benchmarks__/`, and all feature subdirectories per the layout in `proposal.md`.
- [ ] Write `package.json` at version `0.1.0` with `"type": "module"`, `"sideEffects": false`, full `exports` map, deps: `@suaveplan/audio-core workspace:^`, `@suaveplan/error workspace:^`, `@suaveplan/types workspace:^`, `@suaveplan/opentelemetry workspace:^`, `zod catalog:forms`.
- [ ] Write `tsconfig.json` extending `@suaveplan/typescript-config/library.json`.
- [ ] Write `vitest.config.ts` using `createTestConfig()` from `@suaveplan/testing/config`.
- [ ] Add `lint`, `typecheck`, `test`, `test:coverage`, `build`, `docs:check` scripts.

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## 2. Types + errors

- [ ] Write `src/error-codes.ts` — `PITCHErrorCode`, `AUDIO_ANALYSIS_PITCH_ERROR_METADATA`, `registerAudioAnalysisErrorCodes()`.
- [ ] Write Zod schemas: `PitchDetectorOptionsSchema`, `PitchResultSchema`, `KeyDetectorOptionsSchema`, `KeyResultSchema`, `ChordResultSchema`.

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## 3. Algorithms

- [ ] Implement `yin.ts` — YIN pitch detection algorithm.
- [ ] Write `yin.test.ts` and `yin.md` (≥200 words).
- [ ] Implement `chromagram.ts` — 12-bin pitch class profile from magnitude spectrum.
- [ ] Write `chromagram.test.ts` and `chromagram.md` (≥200 words).
- [ ] Implement `key-finding.ts` — Krumhansl-Schmuckler and Temperley key profiles.
- [ ] Write `key-finding.test.ts` and `key-finding.md` (≥200 words).
- [ ] Implement `chord-matching.ts` — template matching for chord recognition.
- [ ] Write `chord-matching.test.ts` and `chord-matching.md` (≥200 words).

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## 4. Detectors

- [ ] Implement `PitchDetector` class with `analyze()`, `analyzeStream()`, `analyzeBlock()`.
- [ ] Write `pitch-detector.test.ts` and `pitch-detector.md` (≥200 words).
- [ ] Implement `KeyDetector` class with `analyze()`, `analyzeStream()`.
- [ ] Write `key-detector.test.ts` and `key-detector.md` (≥200 words).
- [ ] Implement `ChordDetector` class with `analyze()`, `analyzeStream()`.
- [ ] Write `chord-detector.test.ts` and `chord-detector.md` (≥200 words).
- [ ] Wire OTel: spans, counters, histograms per detector.

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## 5. Benchmarks

- [ ] Write `src/__benchmarks__/pitch.bench.ts` — pitch detect 1-minute track, key detect 1-minute track.

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## 6. Tests

- [ ] Write `tests/integration.test.ts` — full pitch/key/chord round-trip on real audio fixture.
- [ ] Write `tests/property.test.ts` (fast-check) — sine wave frequency → exact pitch, confidence in [0,1].

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## 7. Docs + verify + publish

- [ ] All co-located `.md` files (≥200 words each).
- [ ] Write `README.md` at package root.
- [ ] `bunx turbo lint typecheck test --filter=@suaveplan/audio-analysis-pitch` — green.
- [ ] `bunx turbo test:coverage --filter=@suaveplan/audio-analysis-pitch` — 100%.
- [ ] `bun scripts/publish.ts --package @suaveplan/audio-analysis-pitch`.
- [ ] Fold `specs/audio-analysis-pitch/spec.md` into `openspec/specs/audio-analysis-pitch/spec.md`.
- [ ] Archive to `openspec/archive/2026-05-14-enterprise-audio-analysis-pitch/`.