docs: jam knowledgebase plan, backlog, curricula + /kb-expand loop skill

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.claude/skills/kb-expand/SKILL.md

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+---
+name: kb-expand
+description: Expand the JamBuddy jam knowledgebase by exactly one style × instrument cell — research, author, validate, commit. Run repeatedly (or via /loop) to fill the backlog in docs/kb-backlog.md.
+---
+
+# KB Expand — one cell per session
+
+You are expanding JamBuddy's jam knowledgebase: intermediate-level standard progressions and ways to play them, per style × instrument. **Do exactly one cell, end to end.** Small, validated, committed.
+
+## Steps
+
+### 1. Orient (always, every session)
+Read, in this order:
+- `docs/kb-plan.md` — architecture, schema conventions, quality gates, success criteria
+- `docs/kb-backlog.md` — the queue
+- `src/data/kb/SCHEMA.md` and the gold standard `src/data/kb/jazz/guitar.js` — **if they exist**
+- `docs/progression-repertoire.md` §1 — cross-check progressions for the style
+- `docs/learn-curriculum.md` — the intermediate level definition for the instrument
+
+### 2. Claim a cell
+Take the **first `todo` cell** in the backlog (respect the order: bootstrap → guitar → piano → bass). Mark it `in-progress` in `docs/kb-backlog.md`.
+
+**If the foundation doesn't exist yet (no `src/data/kb/`), this session is Session 0:** build `src/data/kb/` with `index.js` registry, `SCHEMA.md` (formats from kb-plan.md §1, one fully-worked example, the musician checklist from §2), `scripts/validate-kb.mjs` (all mechanical checks from kb-plan.md §2 — especially the pitch-class verification of guitar shapes against chord qualities from `src/lib/theory.js` CHORD_TYPES), and the **jazz/guitar** cell as the gold standard. That is one full session; stop after it.
+
+### 3. Research
+Dispatch 1-2 web-research subagents for the claimed style × instrument:
+- the style's standard progressions (verify against `docs/progression-repertoire.md`; add style-specific ones with named sources)
+- 2-3 genuinely different intermediate ways to play each progression on this instrument (voicings with exact frets/fingerings for guitar, degree recipes for piano, line patterns for bass)
+- comping rhythm(s) characteristic of the style, improv guidance (scales over each chord, target notes, 1-2 licks)
+- require named sources/URLs in the agent's report
+
+### 4. Author
+Write `src/data/kb/<style>/progressions.js` (if new style) and `src/data/kb/<style>/<instrument>.js` per SCHEMA.md. Key-agnostic only: degrees and movable shapes (`rootStr` + `offsets`), open shapes with `onlyRoot`. Qualities must be keys of `CHORD_TYPES` in `src/lib/theory.js`. Register the style in `src/data/kb/index.js`.
+
+### 5. Validate — hard gate
+- `node scripts/validate-kb.mjs` must pass. Fix content, don't weaken the validator.
+- Run the musician checklist in SCHEMA.md; cut or fix anything that fails it.
+- `npm run build` must pass.
+
+### 6. Record and commit
+- Backlog: mark the cell `done (YYYY-MM-DD, N progressions × M plays)`.
+- Commit on the current branch: `kb: add <style> <instrument> pack` (or `kb: bootstrap foundation + jazz guitar gold standard`). Do not push unless asked.
+
+### 7. Report
+Tell the user: what was added (progressions, plays, sources), validator result, and **the next cell in the queue**. If a UI milestone in the backlog just became unblocked (e.g. Jam Guide MVP after cell 0), say so explicitly.
+
+## Rules
+- One cell per invocation. Never start a second cell, even if the first went quickly.
+- Never commit content that fails the validator; never relax a validator rule to make content pass — flag the conflict to the user instead.
+- Intermediate level: no 5+ fret stretches, no advanced-only voicings without an intermediate alternative in the same play set.
+- Plays per progression must be idiomatically different (register/density/technique), not transpositions of each other.

GOAL.md

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+# GOAL — From Detection to Direction
+
+WhatTheFlat already solves the hard live problem: **knowing what key and chords people are playing in a jam, in real time.** This document defines the next level, in two parts:
+
+1. **Chord progressions** — make it easier to work with *different* progressions: a bigger genre repertoire, clearer "1-5-4"-style readout of the detected loop, a builder where you place chords yourself, and alternative voicings for every chord in a progression.
+2. **Learn** — expand the education section for the player who already knows the basics and is confident enough to jam, but wants to go next level.
+
+Supporting research and full repertoires live in:
+
+- [`docs/progression-repertoire.md`](docs/progression-repertoire.md) — genre-by-genre progression tables, substitution rules, voicing data sources, UX patterns from existing tools
+- [`docs/learn-curriculum.md`](docs/learn-curriculum.md) — intermediate training methods for guitar, piano, and bass, with drills and how app features map onto them
+- [`docs/kb-plan.md`](docs/kb-plan.md) — the **jam knowledgebase**: styles × instruments × progressions × voicings, the `/kb-expand` session loop that grows it ([`docs/kb-backlog.md`](docs/kb-backlog.md)), and the **Jam Guide** panel that renders it live at the bottom of the app
+
+---
+
+## Part 1 — Chord progressions
+
+### Where we are
+
+- `PROGRESSIONS` in `src/lib/theory.js` holds **14 hardcoded progressions across 7 genres** (Pop, Blues, Folk, Jazz, Rock, '50s, Flamenco). These drive `ProgressionSuggestions.jsx`.
+- `detectRepeatingProgression()` finds the repeating loop in chord history; `ProgressionBanner.jsx` already shows it with Roman numerals (I–V–IV) via `toRomanNumeral()`.
+- `EducationPanel.jsx` + `src/lib/education.js` carry 15 famous progressions with substitutions and style variations.
+- `src/lib/voicings.js` has ~50 guitar shapes (open + barre) across 14 chord types; no inversions, no triad string-sets, thin piano coverage.
+- There is **no way to enter or arrange a progression manually** — everything is detection-driven.
+
+### Goals
+
+**G1 — Expanded genre repertoire (data, not code).**
+Grow `PROGRESSIONS` from 7 to ~12 genres using the researched tables in `docs/progression-repertoire.md`: Funk (Dorian i7–IV7 vamps), Reggae (two-chord skanks), Country (V/V secondary dominant moves), R&B/Neo-soul (iii–vi–ii–V, 6-2-5-1), Gospel (chained 2-5-1s), plus blues variants (quick-change, minor blues) and the J-pop "Royal Road" (IV–V–iii–vi). Progressions stay in the existing `{ name, rn, degrees }` format so suggestions, Roman numerals and key mapping keep working unchanged.
+
+**G2 — Numeral clarity ("is this 1-5-4?").**
+The loop banner already shows Roman numerals; add a **Nashville-number display option** (1-5-4 instead of I-V-IV) since that is how musicians call changes at a jam. One formatting layer over `toRomanNumeral`, toggled in Settings.
+
+**G3 — Progression Builder (drag and drop).**
+A panel where the user assembles a progression by hand:
+- A **key-relative chord palette** (Hookpad's best idea): the diatonic chords of the current detected/locked key, one tap to add, with borrowed-chord palette (iv, ♭VII, ♭VI, V/V…) one level deeper.
+- Slots that can be **reordered by drag and drop**, with live Roman/Nashville numerals under each chord.
+- Tap any slot → **alternative voicings** for that chord (G4).
+- Seeded from the detected loop ("send loop to builder") so a jam can be captured, edited, and varied.
+- Variation buttons per chord powered by the substitution taxonomy (diatonic swap, borrow, secondary dominant, 7th/sus/add9 color) — the rules are in `docs/progression-repertoire.md` §2.
+
+**G4 — Alternative voicings per progression chord.**
+- **Guitar:** extend `voicings.js` with CAGED positions and triads on string-sets (top-3 / middle-3), or adopt the MIT-licensed [`tombatossals/chords-db`](https://github.com/tombatossals/chords-db) dataset (multiple positions per chord, JSON, with a companion React SVG renderer).
+- **Piano:** generate voicings from interval recipes rather than data files — root position, inversions, shells (1-3-7), rootless A (3-5-7-9) / B (7-9-3-5) — choosing the inversion that minimizes movement from the previous chord (voice-leading distance).
+- Surface these in the Builder (G3) and in `CurrentJamPanel` voicing strips.
+
+---
+
+## Part 2 — Learn: basics → jam-ready next level
+
+### Audience
+
+Not step one. The target player already knows open/barre chords (guitar), triads and simple lead sheets (piano), roots and simple scales (bass) — and is confident enough to show up at a jam. The Learn section's job is to take them **from "can survive a jam" to "makes the jam better."**
+
+### What the research says (full detail in `docs/learn-curriculum.md`)
+
+Across guitar, piano, and bass pedagogy (Berklee methods, Justin Guitar grades 4–6, Tomo Fujita, Mark Levine, Open Studio, PianoGroove, Scott's Bass Lessons, TalkingBass, Ed Friedland), the intermediate-to-advanced jump converges on four pillars:
+
+| Pillar | Guitar | Piano | Bass |
+|---|---|---|---|
+| **Fretboard/keyboard liberation** | CAGED, triads on string sets, connecting pentatonic boxes | Inversions in all keys, voice leading | Neck zones, chord-tone arpeggios everywhere |
+| **Playing the changes** | Chord-tone targeting, guide tones (3rds & 7ths) | Shell + rootless voicings, sus/add9 colors | Walking lines, chromatic approach notes |
+| **Ensemble skills** | Small voicings, register discipline, comping | Comping rhythms (Charleston…), "rule of 1", staying out of the bass lane | Pocket/drummer lock, ghost notes, subdivision switching |
+| **Functional ears** | Hearing I-IV-V / vi-IV-I-V by bass line | Nashville numbers, 12-key transposition | Singing root movement, predicting the V |
+
+### Goals
+
+**L1 — Practice drills tab.**
+Add a drills library to the Learn section: per instrument, per pillar, the concrete drills from the curriculum doc (e.g. "first note after every chord change = the 3rd", "Charleston comping ladder", "W|H|H chromatic walkup"). Keyed to the *current detected key and loop* so every drill is in today's jam context, not abstract C major.
+
+**L2 — Detection-powered feedback (the unfair advantage).**
+No practice app can hear the player; this one can. Phased:
+- **Target-note highlighting:** on each detected chord change, highlight the new chord's 3rd/7th on the fretboard/piano for a beat (drill scaffold — uses existing tier rendering).
+- **Next-chord preview tier:** when a loop is detected, show the *upcoming* chord's root and its chromatic approach notes (the bassist's walking-line scaffold).
+- **Chord-tone hit rate:** classify detected notes against the current chord (chord tone / scale tone / outside) and show a session score.
+- **Pocket report:** extend the onset/BPM pipeline to show timing drift against the established grid.
+
+**L3 — Ear training from your own jam.**
+A quiz mode that hides the chord banner and asks the user to name the progression in numbers before revealing — using the *user's own chord history* as the corpus. Converts the existing detection + `toRomanNumeral` into the functional ear training every method prescribes.
+
+**L4 — Mode-difference teaching.**
+When the user manually switches mode (the documented K-S limitation — by design), briefly highlight the *difference notes* (e.g. the raised 6th going minor → Dorian) on the instrument views. Turns a limitation into a lesson.
+
+---
+
+## What we need to go next level — priorities
+
+| # | Item | Effort | Why first |
+|---|---|---|---|
+| 1 | **G1** Genre repertoire expansion | S (data only) | Immediate value, zero architectural risk |
+| 2 | **G2** Nashville number toggle | S | Directly answers "is it 1-5-4", jam-native language |
+| 3 | **G3** Progression Builder MVP (palette + reorder + numerals) | M | The single most-requested workflow gap |
+| 4 | **L1** Drills tab seeded from curriculum doc | M (content + UI) | Makes Learn level-appropriate |
+| 5 | **G4** Voicing alternatives (guitar string-sets + piano recipes) | M | Feeds both Builder and Learn |
+| 6 | **L2** Target-note highlighting + next-chord preview | M | First detection-powered trainer, reuses tier rendering |
+| 7 | **L3** Ear-training quiz on own history | M | High pedagogical value, small surface |
+| 8 | **L2** Hit-rate scoring + pocket report | L | Needs tuning of pitch/onset classification |
+| 9 | **G3** Builder phase 2: borrowed palette, variation buttons, loop import | L | Builds on MVP + substitution rules |
+| 10 | **KB** Knowledgebase + Jam Guide panel (see `docs/kb-plan.md`) | L, but looped in S-sized sessions via `/kb-expand` | The style × instrument playbook that powers improv learning |
+
+### How we execute
+
+Knowledgebase work runs as **looped sessions**: `/kb-expand` does exactly one style × instrument cell (research → author → validate → commit), driven by the queue in `docs/kb-backlog.md`. Tranches run on a dedicated branch — e.g. an hourly `/loop /kb-expand` for a working day — and **end with a pull request** so a whole tranche is reviewed in one place. First tranche (started 2026-06-12, branch `kb-expansion`): Session 0 bootstrap + the first guitar style cells, hourly for 8 hours, PR to `main` at the end.
+
+### Definition of "next level" (success criteria)
+
+- A jammer can glance at the app and call the loop in numbers ("it's a 1-5-4").
+- Suggestions cover the genres people actually jam (funk/reggae/R&B/gospel included), not just pop/blues.
+- A user can lay out their own progression, drag chords around, and see 3+ ways to voice every chord on their instrument.
+- The Learn section gives an intermediate guitarist, pianist, or bassist a *specific* next drill in the key they're jamming in right now — and at least one drill where the app verifies them by listening.

docs/kb-backlog.md

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+# KB Expansion Backlog
+
+The queue for the `/kb-expand` loop. One cell per session, top-to-bottom. Protocol and schema: [`docs/kb-plan.md`](kb-plan.md). Statuses: `todo` → `in-progress` → `done (YYYY-MM-DD, coverage)`.
+
+## Phase 0 — Foundation (must be first)
+
+| # | Cell | Status |
+|---|---|---|
+| 0 | Bootstrap: `src/data/kb/` + `SCHEMA.md` + `scripts/validate-kb.mjs` + `kb/index.js` + **jazz/guitar gold standard** | todo |
+
+## Guitar
+
+| # | Style | Status |
+|---|---|---|
+| 1 | Jazz (part of bootstrap) | todo |
+| 2 | Blues | todo |
+| 3 | Rock | todo |
+| 4 | Bossa Nova | todo |
+| 5 | Funk | todo |
+| 6 | Reggae | todo |
+| 7 | Country / Folk | todo |
+| 8 | R&B / Neo-soul | todo |
+| 9 | Gospel | todo |
+| 10 | Pop | todo |
+
+## Piano
+
+| # | Style | Status |
+|---|---|---|
+| 11 | Jazz | todo |
+| 12 | Blues | todo |
+| 13 | Bossa Nova | todo |
+| 14 | Gospel | todo |
+| 15 | R&B / Neo-soul | todo |
+| 16 | Pop | todo |
+| 17 | Rock | todo |
+| 18 | Funk | todo |
+| 19 | Country / Folk | todo |
+| 20 | Reggae | todo |
+
+## Bass
+
+| # | Style | Status |
+|---|---|---|
+| 21 | Blues | todo |
+| 22 | Jazz | todo |
+| 23 | Funk | todo |
+| 24 | Reggae | todo |
+| 25 | Rock | todo |
+| 26 | Bossa Nova | todo |
+| 27 | R&B / Neo-soul | todo |
+| 28 | Country / Folk | todo |
+| 29 | Gospel | todo |
+| 30 | Pop | todo |
+
+## UI milestones (interleave when their data exists)
+
+| Milestone | Depends on | Status |
+|---|---|---|
+| Jam Guide MVP (panel, matching, `ChordDiagram.jsx`, live sync) | cell 0 | todo |
+| `MiniPiano.jsx` + recipe resolver | cell 11 | todo |
+| Bass pattern renderer | cell 21 | todo |
+| Improv layer (licks/tabs display) | a few guitar cells | todo |
+
+> Notes for sessions: piano style order front-loads the styles where piano voicings differ most (jazz/gospel/neo-soul); bass order front-loads line-driven styles (blues/jazz/funk). Adjust freely — order is a default, not a rule.

docs/kb-plan.md

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+# Knowledgebase Plan — Styles × Instruments × Progressions × Voicings
+
+The plan for building JamBuddy's **jam knowledgebase**: an intermediate guide to the standard progressions of each style (Jazz, Blues, Rock, Bossa Nova, …) and the different ways to *play* them per instrument (guitar first, then piano, then bass) — expandable one session at a time via a repeatable loop, and rendered live in a large **Jam Guide** panel at the bottom of the app.
+
+Three principles drive everything:
+
+1. **Key-agnostic data.** Everything is stored as scale degrees and movable shapes, never absolute chords. The app detects the key; one KB entry renders in all 12 keys. This is the same convention `PROGRESSIONS.degrees` and the movable shapes in `voicings.js` already use.
+2. **Machine-verifiable quality.** A validator proves every voicing actually contains the chord's tones before content lands. That's what makes agent-generated content trustworthy over many loop iterations.
+3. **One bounded cell per session.** Each expansion session completes exactly one style × instrument cell (researched, authored, validated, committed). Small enough to review, big enough to matter.
+
+---
+
+## 1. Architecture
+
+```
+src/data/kb/
+  index.js                 — registry aggregating all styles (UI reads only this)
+  SCHEMA.md                — the authoring contract (formats below, with one full example)
+  jazz/
+    meta.js                — { id, label, feel, tempoRange, character }
+    progressions.js        — the style's standard progressions (instrument-independent)
+    guitar.js              — guitar pack: plays + comping + improv
+    piano.js               — piano pack
+    bass.js                — bass pack
+  blues/ …                 — same shape per style
+scripts/
+  validate-kb.mjs          — quality gate, run with `node scripts/validate-kb.mjs`
+docs/
+  kb-backlog.md            — the cell matrix with statuses (the loop's queue)
+```
+
+`index.js` imports whatever style folders exist — the Jam Guide's style tabs grow automatically as the loop fills cells. A style is usable for one instrument before the others exist (guitar-first rollout).
+
+### Progression entry (per style)
+
+```js
+// kb/jazz/progressions.js
+export default [
+  {
+    id: 'jazz-251-major',
+    name: 'ii–V–I',
+    rn: ['ii7', 'V7', 'Imaj7'],
+    degrees: [2, 7, 0],                    // semitone offsets from key root
+    qualities: ['min7', 'dom7', 'maj7'],   // keys of CHORD_TYPES in theory.js
+    bars: [1, 1, 2],
+    mode: 'major',
+    songs: ['Autumn Leaves', 'All The Things You Are'],
+    tip: 'The 7th of each chord resolves down a half-step to the 3rd of the next.',
+  },
+  // … 4-8 progressions per style (see docs/progression-repertoire.md §1 for the lists)
+]
+```
+
+### Instrument pack — guitar
+
+```js
+// kb/jazz/guitar.js
+export default {
+  styleIntro: '2-3 sentences on the guitarist's role in this style.',
+  comping: [{ label: 'Four-to-the-bar (Freddie Green)', rhythm: '♩ ♩ ♩ ♩', description: '…' }],
+  plays: {
+    'jazz-251-major': [                    // ≥2 "ways to play" per progression
+      {
+        label: 'Shell voicings',
+        level: 'intermediate',
+        chords: [                          // one entry per progression step
+          { shape: { rootStr: 5, offsets: ['x', 0, 'x', 0, 1, 'x'], fingers: [0,1,0,2,3,0] },
+            note: 'root–♭7–♭3' },
+          // …
+        ],
+        tips: 'Stay light; the 3rds and 7ths do all the work.',
+      },
+      { label: 'Drop-2 on top four strings', /* … */ },
+    ],
+  },
+  improv: {
+    scales: [{ over: 'ii7', scale: 'dorian', why: '…' }],
+    targetNotes: 'Land the 3rd of each chord on beat 1.',
+    licks: [{ tab: 'e|---…', description: '…', over: 'jazz-251-major' }],
+  },
+}
+```
+
+**Shape format** follows the existing `voicings.js` convention so the renderer is shared: movable shapes use `rootStr` + `offsets` relative to the root fret (renders in any key); open shapes use absolute `frets` + `onlyRoot` (pitch class) and only render when the key matches. Strings are arrays of 6, low-E first, `'x'` = muted.
+
+### Instrument pack — piano
+
+Voicings are **interval recipes** resolved per chord quality (no fingering data needed):
+
+```js
+plays: {
+  'jazz-251-major': [
+    {
+      label: 'Rootless A/B alternation',
+      level: 'intermediate',
+      chords: [
+        { recipe: { LH: ['3', '5', '7', '9'] }, note: 'Type A' },     // ii7
+        { recipe: { LH: ['7', '9', '3', '13'] }, note: 'Type B' },    // V7
+        { recipe: { LH: ['3', '5', '7', '9'] }, note: 'Type A' },     // Imaj7
+      ],
+      register: 'top note between C4 and C5',
+      tips: 'Alternate types so inner voices barely move.',
+    },
+  ],
+}
+```
+
+Degrees are chord-degree strings (`'1' '3' 'b7' '9' '13'`); the resolver maps them through the chord quality's intervals (which `theory.js` chord templates already encode).
+
+### Instrument pack — bass
+
+Line patterns per progression step, in degrees plus approach annotations:
+
+```js
+plays: {
+  'blues-12bar': [
+    {
+      label: 'Walking, chromatic approach',
+      level: 'intermediate',
+      bars: [{ beats: ['R', '3', '5', 'chrom→next'] } /* … per bar */],
+      tips: 'Beat 1 is always the new root; beat 4 walks into it.',
+    },
+  ],
+}
+```
+
+---
+
+## 2. Quality gates
+
+### Mechanical — `scripts/validate-kb.mjs` (must pass before any commit)
+
+- ids unique; every `plays` key references an existing progression id; `chords`/`bars` length matches the progression length
+- `degrees` ∈ 0–11; `qualities` are keys of `CHORD_TYPES`; `mode` is a known mode
+- guitar shapes: 6 entries per array, frets 0–15, **fret span ≤ 4** (intermediate hands), and — the strong check — the shape's computed pitch classes (standard tuning EADGBE) must contain the chord's root and defining tones (3rd/7th or quality equivalent) and contain **no out-of-chord tones**
+- piano recipes: every degree resolvable for that chord quality
+- coverage per cell: ≥ 4 progressions, ≥ 2 plays per progression, improv section present (guitar/piano), styleIntro present
+
+### Musician checklist (human/agent self-review, in SCHEMA.md)
+
+- Are the plays *idiomatically different* (register, density, difficulty), not just transpositions of each other?
+- Is each play genuinely intermediate — no 5-fret stretches, no 2-octave rootless clusters?
+- Does the style actually sound like the style (bossa ≠ jazz with different labels: distinct rhythm descriptions)?
+- Do tips teach a *transferable* idea (voice leading, register, space), not just "play this"?
+
+---
+
+## 3. The expansion loop
+
+### The queue
+
+`docs/kb-backlog.md` holds the matrix of cells with statuses (`todo` / `in-progress` / `done` + date + coverage). Order: **all guitar cells first** (most voicing complexity — it sets the quality bar), then piano, then bass. Style priority within each instrument: jazz → blues → rock → bossa → funk → reggae → country/folk → R&B/neo-soul → gospel → pop.
+
+### The session protocol (encoded as the `/kb-expand` project skill)
+
+Each session:
+
+1. **Orient** — read this plan, `SCHEMA.md`, the backlog, and the gold-standard cell (`kb/jazz/guitar.js`, the first one built).
+2. **Claim** — take the first `todo` cell, mark it `in-progress`.
+3. **Research** — dispatch web-research agent(s) for that style × instrument: the style's standard progressions (cross-check against `docs/progression-repertoire.md`), the 2-3 idiomatic intermediate ways to play each, comping rhythms, improv approach. Named sources required.
+4. **Author** — write `progressions.js` (if the style is new) and the instrument pack, conforming to SCHEMA.md.
+5. **Validate** — run `node scripts/validate-kb.mjs`; fix until green; run the musician checklist.
+6. **Integrate** — register the style in `kb/index.js`; `npm run build` must pass.
+7. **Record** — mark the cell `done` with date + coverage stats in the backlog; commit (`kb: add <style> <instrument> pack`).
+8. **Report** — summarize what was added and name the next cell.
+
+**Session 0 (bootstrap):** if `src/data/kb/`, `SCHEMA.md`, or the validator don't exist yet, the first session builds them *plus* the jazz/guitar gold-standard cell. Every later session imitates that exemplar.
+
+### How to run it
+
+- One session: type **`/kb-expand`** — does exactly one cell.
+- Several in a row: `/loop /kb-expand` and let it self-pace, or run `/kb-expand` whenever there's time.
+- Review cadence: cells are individual commits on a branch — review/merge per instrument tranche if preferred.
+
+30 cells ≈ 30 short sessions; guitar's 10 cells deliver user-visible value immediately because the Jam Guide reads whatever exists.
+
+---
+
+## 4. The Jam Guide panel (UI)
+
+A large panel at the **bottom of the main scroll** — while jamming you scroll down and the current progression's playbook is laid out to fit the screen.
+
+```
+┌─ JAM GUIDE ─────────────────────────────── [Guitar|Piano|Bass]  [Jazz][Blues][Rock][Bossa]… ─┐
+│  Matched: ii–V–I in G major        your loop:  Am7 → D7 → Gmaj7                              │
+│                                                                                              │
+│                 Am7 (ii7)         D7 (V7)          Gmaj7 (Imaj7)                             │
+│                 ▼ playing now                                                                │
+│  Shells         [diagram]         [diagram]        [diagram]       root–3–7, four-to-the-bar │
+│  Drop-2         [diagram]         [diagram]        [diagram]       top-4 strings, stays high │
+│  Triads 1-3     [diagram]         [diagram]        [diagram]       fills between vocal lines │
+│  ─────────────────────────────────────────────────────────────────────────────              │
+│  IMPROV   D dorian → G mixo → G major  ·  target the 3rds: C → F# → B  ·  lick ▸ tab…        │
+└──────────────────────────────────────────────────────────────────────────────────────────────┘
+```
+
+- **Component:** `JamGuide.jsx`, mounted last in `App.jsx`; collapsed header always visible, expands to ~70vh.
+- **Inputs:** `keyInfo`, `detectedProgression`, `currentChord` — plus instrument + style selection (persisted in settings; style tabs are generated from `kb/index.js`, so the panel grows as the loop runs).
+- **Matching:** convert the detected loop to degrees relative to the key root, match against the selected style's progressions **rotation-invariantly** (same canonicalization idea as `detectRepeatingProgression`). No match → fallback: per-chord voicing alternatives from `voicings.js`, so the panel is never empty.
+- **Live sync:** the active chord column highlights using the loop-position logic in `ProgressionBanner.jsx` (`findLoopPosition` — extract it to a shared util). The player reads the *next* voicing in time, in rhythm with the band.
+- **Diagrams:** new small renderers — `ChordDiagram.jsx` (6-string × 5-fret SVG grid, consumes the shape format), `MiniPiano.jsx` (~2-octave SVG, highlights resolved recipe notes), bass patterns as degree badges (R · 3 · 5 · ♭7) over a mini string diagram. Reuse design tokens (`bg-panel`, `border-border`, accent purple for chord tones).
+- **Smart fit:** CSS grid — columns = progression chords (4–6), rows = plays; rows beyond what fits collapse behind "more ways ▾"; diagrams scale to column width; on narrow windows the grid flips to one play per row, chords scrolling horizontally.
+- **Key-aware rendering:** movable shapes get their fret position computed from the detected key; open shapes appear only when the chord's root matches; piano recipes resolve through the chord quality. All 12 keys for free, per principle 1.
+
+---
+
+## 5. Phases
+
+| Phase | What | Outcome |
+|---|---|---|
+| 0 | Foundation: `kb/` dirs, `SCHEMA.md`, validator, backlog, `/kb-expand` skill, jazz/guitar gold standard | The loop exists and has an exemplar |
+| 1 | Jam Guide MVP: panel + matching + guitar `ChordDiagram` + live sync | jazz/guitar visible in the app while jamming |
+| 2 | Loop guitar cells: blues, rock, bossa, funk, reggae, country, R&B, gospel, pop | Full guitar guide across styles |
+| 3 | Piano: `MiniPiano` renderer + recipe resolver, loop piano cells | Second instrument live |
+| 4 | Bass: pattern renderer, loop bass cells | Third instrument live |
+| 5 | Polish: improv layer with tabs/licks, Progression Builder integration (GOAL G3), ToneGym-style tap-to-hear | Guide ↔ Builder round-trip |
+
+### Success criteria
+
+- During a jam, scrolling to the Jam Guide shows ≥ 3 ways to play the detected progression on the selected instrument, in the detected key, with the active chord highlighted in time.
+- `/kb-expand` completes a cell in one session with the validator green, no hand-holding.
+- A new style added by the loop appears in the UI with **zero code changes** (data + registry only).
+- An intermediate player can switch Jazz → Bossa over the same ii–V–I and see *genuinely different* voicings and rhythm guidance.

docs/learn-curriculum.md

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+# Learn Curriculum — Intermediate, Jam-Ready Players
+
+Research-backed training repertoire for the Learn section. Companion to [`GOAL.md`](../GOAL.md) Part 2. Audience: players who know the basics and can survive a jam — the goal is making them better *in* the jam. Not beginner material.
+
+Across guitar, piano, and bass pedagogy the intermediate→advanced jump converges on four pillars: **instrument liberation** (play anything anywhere), **playing the changes** (chord-tone awareness), **ensemble skills** (space, register, pocket), and **functional ears** (hearing 1-5-6-4). The per-instrument curricula below feed both the Learn UI and the knowledgebase (see `docs/kb-plan.md`).
+
+---
+
+## Guitar
+
+### Skill taxonomy (rough order)
+
+**Tier A — Fretboard liberation**
+1. CAGED system fluency — locate any chord in 5 places instantly (Fretboard Logic, Pickup Music)
+2. Triads on string sets — major/minor triads + inversions on strings 1-3, 2-4, 3-5 (Justin Guitar Grade 5, Leavitt Vol. 2)
+3. Connecting pentatonic boxes — the box 2↔3 seam is the documented weak point
+4. Scale-over-chord mapping — seeing the chord *inside* the scale shape
+
+**Tier B — Playing the changes**
+5. Chord-tone / target-note soloing — land on a chord tone on beat 1 of each change
+6. Guide tones (3rds & 7ths) — the 7th of one chord resolves to the 3rd of the next
+7. Phrasing across positions
+
+**Tier C — Ensemble skills**
+8. Comping with small triad voicings — stay out of the vocalist's/keys' register
+9. Internal time — metronome on beats 2 & 4, then no click (Tomo Fujita's core emphasis)
+10. Ear-led playing — "let your ears lead you instead of your eyes" (Fujita)
+
+**Tier D — Functional ears**
+11. Progression recognition by ear — track the bass line first
+12. Modal awareness — how Dorian/Mixolydian overlap shapes you already know
+13. Transcribing & daily riff-writing — the recurring plateau fix
+
+### Top drills
+1. **Triad voice-leading over 12-bar blues** — only close triads on one string set; on every change move each finger to the *nearest* note of the next triad. Forces inversions + minimal-motion voice leading at once.
+2. **One-CAGED-position soloing** — improvise using only one grip's chord tones + surrounding scale notes; shift position each chorus. Welds chord, arpeggio, and scale into one visual unit.
+3. **Target-note drill** — first note after each chord change must be the 3rd (then 7ths, then 7th→3rd resolutions); pentatonic filler in between. Pure pentatonic playing suddenly "follows the changes".
+4. **Pentatonic seam drill** — ascend box 1, exit through a named seam note into box 2, etc. Shifts become melodic destinations.
+5. **Metronome on 2 & 4** — click as the snare backbeat; progress to click once per bar, then none.
+6. **Comping ladder** — comp behind a recorded soloist using only 3-string triads above fret 5, varying rhythm/dynamics, never register-clashing.
+7. **Daily progression dictation** — 10-15 min naming I-IV-V vs vi-IV-I-V vs ii-V-I from songs, bass line first.
+
+### Sources
+Fretboard Logic (Bill Edwards) · Justin Guitar Grades 4–6 · Tomo Fujita *Accelerate Your Guitar Playing* (Berklee) · Leavitt *A Modern Method for Guitar* Vol. 2 · Absolutely Understand Guitar · Pickup Music CAGED pathway · fundamental-changes.com (guide tones) · TrueFire (box connection, plateaus) · Premier Guitar "Rhythm Rules" · zotzinguitarlessons.com (triads in 12 keys) · ToneGym / tonedear.com · stringshock.com & jazzguitartoday.com (jam etiquette)
+
+---
+
+## Piano / Keys
+
+### Skill taxonomy (rough order)
+
+**Tier 1 — Harmonic vocabulary**
+1. Triad inversions in all 12 keys — grab any chord near the current hand position
+2. Voice leading — minimum-distance inversion choice; the biggest "amateur → pro" jump
+3. Shell voicings (root–3–7) — light, clear, gateway to comping (Open Studio, PianoGroove)
+4. Sus2/sus4/add9 colors and slash chords — pop/worship vocabulary
+5. Rootless voicings — Type A (3-5-7-9), Type B (7-9-3-5); top note between C4–C5
+
+**Tier 2 — Rhythm & ensemble role**
+6. Comping rhythms — Charleston, reverse Charleston, Red Garland pattern, anticipations
+7. Register discipline — LH stays above ~G3 when a bassist is present
+8. Density discipline ("rule of 1") — in a 5-piece band, play 1/5 of the music
+9. Hand-role splitting — LH harmony/groove anchor, RH color and answers
+
+**Tier 3 — Functional/ear skills**
+10. Thinking in numbers (Nashville Number System / Roman numerals)
+11. Progression recognition by ear — bass line + emotional flow of each degree
+12. Transposition fluency — known songs in all 12 keys via the number method
+13. Sight-comping — realize an unfamiliar lead sheet at tempo (Berklee keyboard method)
+
+**Tier 4 — Bandstand**
+14. Form-keeping under pressure — never lose bar 1
+15. Improvising over changes — chord tones → pentatonics → scale tones
+16. Repertoire in 2-3 keys from memory
+
+### Top drills
+1. **Voice-led progression loop in 12 keys** — I–V–vi–IV with minimum hand movement (C → G/B → Am → F/A), through the circle of fifths. Self-grading: you can see and hear when you jump.
+2. **Shell ii–V–I cycle** — root+3+7 through all keys, alternating types so 3rds/7ths swap and resolve by half-step. The core voice-leading mechanic made physical.
+3. **Charleston metronome ladder** — one syncopation pattern to automaticity at 80→160 BPM; comping failure in jams is usually rhythmic, not harmonic.
+4. **Backing-track subtraction** — chorus 1 whole notes only; chorus 2 LH only above G3, no roots; chorus 3 RH colors only; chorus 4 two hits per bar. Simulates bandmates occupying frequency space.
+5. **Bass-line ear training** — hum the bass note of each chord in a pop song, convert to numbers, play it.
+6. **One song, twelve keys** — number-chart a known song, new key daily.
+7. **Cold lead-sheet sight-comping** — slow metronome, once through the form, never stopping. Rehearses the actual jam failure mode.
+
+### Sources
+Berklee Online Keyboard Method · Mark Levine *The Jazz Piano Book* · Open Studio Piano Pathway · PianoGroove (rootless voicings, comping) · The Jazz Piano Site (jam prep) · Piano With Jonny (voicings, transposing) · Jens Larsen (comping rhythms) · Pianote (band guide, NNS) · Worship Online / Musicademy / Sweetwater (band role) · ToneDear / ToneGym / Musical U / trainear.com (ear training)
+
+---
+
+## Bass
+
+### Skill taxonomy (rough order)
+1. Fretboard zone mastery — every note to fret 12, lines through each zone (Friedland)
+2. Root-fifth-octave vocabulary — the "safe but musical" jam fallback
+3. Chord-tone fluency — R-3-5-7 of maj/min/dom/m7♭5 anywhere (TalkingBass: chord tones *before* scales)
+4. Scale-tone vs chord-tone discrimination — outline on strong beats, connect on weak
+5. Approach-note technique — chromatic from above/below, W|H|H walkup, dominant approach
+6. Walking bass construction — root on 1, chord tones on 1 & 3, approach into the next root on 4
+7. Subdivision command — straight 8ths / swing / shuffle / 16th funk, switching mid-groove
+8. Pocket / drummer lock — kick matching, ghost notes, dynamic mirroring
+9. Functional ear training — root movement, I/IV/V/vi by function
+10. Real-time harmonic prediction — the V "pushes home", reacting within one pass of the form
+11. Dynamics, touch, space — most cited intermediate→pro separator
+12. Fills and form awareness — fills at bars 4/8 phrase boundaries
+
+### Top drills
+1. **Root-only song stripping** — play only the root of each change by ear; add 5ths and octaves on later passes. Strips songs to harmonic skeleton.
+2. **Arpeggiate the progression** — R-3-5(-7) over I-V-vi-IV in several keys, then inversions, then other neck zones.
+3. **W|H|H chromatic walkup** — between chords a 4th apart: root, whole, half, half (C-D-E♭-E→F). Formulaic forward motion that telegraphs the next chord.
+4. **Walking 12-bar / 1-6-2-5 loop** — a decision every beat about chord vs passing tone (Friedland, SBL 5-step formula).
+5. **2-bar loop challenge** — one groove for 5+ minutes changing only tone/dynamics/note length. Pocket training; exposes drift.
+6. **Subdivision switching** — 2 bars 8ths / 2 bars 16ths at 60-80 BPM; click on 2&4 only; mute the click 4 bars and check.
+7. **Sing-then-play root movement** — sing the roots before touching the bass, then 3rds/5ths/7ths.
+
+### Sources
+Scott's Bass Lessons (Players Path, Groove Trainer) · TalkingBass Chord Tone Essentials · Ed Friedland *Building Walking Bass Lines* · Hal Leonard Bass Method · Berklee Practice Method: Bass · Bass Musician Magazine (drummer lock) · Premier Guitar (jam survival) · StudyBass · Learn Jazz Standards · Jazz Night School (chromatic 4) · onlinebasscourses.com · Functional Ear Trainer
+
+---
+
+## How the app supports this (detection-powered training)
+
+These map to GOAL.md L1–L4; the app's unfair advantage is that it *hears* the player.
+
+1. **Target-note highlighting** — on each detected chord change, flash the new chord's 3rd/7th on the fretboard/piano (guitar drill 3, piano drill 2). Later: score whether the first detected note after the change was a chord tone.
+2. **Voice-leading coach (piano view)** — highlight the *nearest inversion* to the previous chord, common tones marked "hold"; score total semitone travel per progression.
+3. **Next-chord preview tier (bass)** — when a loop is detected, highlight the upcoming chord's root plus its chromatic approach notes a half-step above/below — the walking-line scaffold, one beat ahead.
+4. **Progression ear-trainer on your own jam** — hide the chord banner, ask for the numbers (vi-IV-I-V), reveal. Uses chord history + `toRomanNumeral`; contextual beats abstract drills.
+5. **Pocket report** — extend the onset/BPM histogram to show beat-phase drift (rushing/dragging), plus a 2-&-4-only click synced to the detected tempo.
+6. **Mode-difference teaching** — when the user manually switches mode (the K-S limitation), briefly highlight the difference notes (minor → Dorian = raised 6th).

docs/progression-repertoire.md

@@ -0,0 +1,149 @@
+# Chord Progression Repertoire
+
+Research-backed reference for expanding the progression features. Companion to [`GOAL.md`](../GOAL.md) Part 1. Notation: uppercase = major, lowercase = minor, ° = diminished, 7 = dominant unless marked maj7/m7.
+
+How this maps to code today:
+
+- `PROGRESSIONS` in `src/lib/theory.js` — `{ name, rn, degrees }` per progression; `degrees` are semitone offsets from the key root. This is the format new entries should use.
+- `getSuggestedProgressions(root, mode)` maps degrees → chord names in key; `toRomanNumeral()` converts any chord back to a numeral.
+- `FAMOUS_PROGRESSIONS` in `src/lib/education.js` — richer entries (songs, tips, style variations) for the Learn side.
+
+## 1. Genre-by-genre progression tables
+
+### Pop
+| Progression | Name / notes |
+|---|---|
+| I–V–vi–IV | "Axis of Awesome" — #1 in Hooktheory's corpus of 75k+ analyzed songs |
+| vi–IV–I–V | Same loop rotated to start on vi ("pessimistic axis") |
+| I–vi–IV–V | "Doo-wop" / "'50s progression" |
+| I–IV–vi–V | Common variant (Africa chorus) |
+| IV–V–iii–vi | "Royal Road" — J-pop/anime staple, spreading into Western pop |
+
+### Rock
+| Progression | Name / notes |
+|---|---|
+| I–IV–V | Foundation of rock/blues/country |
+| I–♭VII–IV(–I) | Mixolydian rock cliché (Sweet Home Alabama as V–IV–I rotation) |
+| i–♭VII–♭VI(–V) | Andalusian-derived minor loop; with V = full Andalusian cadence |
+| I–♭III–IV | Blues-rock riff progression (borrowed ♭III) |
+
+### Blues (12-bar family)
+| Progression | Name / notes |
+|---|---|
+| I7×4 / IV7×2, I7×2 / V7, IV7, I7, V7 | Standard 12-bar |
+| Bar 2 → IV7 | "Quick change" / "quick four" |
+| ii7–V7 in bars 9–10, turnaround I–VI7–ii–V7 | Jazz blues |
+| i7–iv7–i7 … ♭VI7–V7–i7 | Minor blues (The Thrill Is Gone) |
+| I–V–IV–IV–I–V–I–V | 8-bar blues (Key to the Highway) |
+
+### Jazz
+| Progression | Name / notes |
+|---|---|
+| ii7–V7–Imaj7 | The fundamental cadence |
+| I–vi–ii–V (also iii–vi–ii–V) | Rhythm changes A / turnaround |
+| III7–VI7–II7–V7 | Rhythm changes bridge (circle of dominants) |
+| iim7♭5–V7♭9–i | Minor ii–V–i |
+| ii7–♭II7–Imaj7 | Tritone-sub cadence |
+| ivm7–♭VII7–Imaj7 | "Backdoor" progression |
+
+### Folk / Country
+| Progression | Name / notes |
+|---|---|
+| I–IV–V(–I) | Core of both genres |
+| I–V–I–IV | Two/three-chord verse pattern |
+| i–♭VII–♭VI | Minor folk descent (Am–G–F) |
+| I–V–vi–iii–IV–I–IV–V | Pachelbel progression |
+| I–II7–V–I | Classic country secondary-dominant (V/V) move |
+
+### Funk
+| Progression | Name / notes |
+|---|---|
+| I7 vamp | James Brown static dominant, voiced as 9th |
+| i7–IV7 | Dorian two-chord vamp — the most common funk pair |
+| i7 / m11 vamp | Minor one-chord groove |
+| ii7–V7 loop | Funk/disco vamp |
+
+Design insight: funk needs few *progressions* but rich *chord qualities* (9, 7♯9, m11, 13sus) — colour lives in the voicing, not the changes.
+
+### Reggae
+| Progression | Name / notes |
+|---|---|
+| I–V or I–IV | Two-chord skank vamps |
+| I–V–vi–IV | No Woman No Cry |
+| i–♭VII(–♭VI) | Minor roots-reggae vamp |
+| I–IV–V | Ska/rocksteady standard |
+
+### R&B / Neo-soul
+| Progression | Name / notes |
+|---|---|
+| ii7–V7–Imaj7 (with 9/11/13 extensions) | Core cadence |
+| iii7–vi7–ii7–V7 | Circle movement from the mediant — neo-soul staple |
+| vi–ii–V–I | "6-2-5-1" cyclical soul loop |
+| Imaj7–IVmaj7 / Imaj7–iii7 | Two-chord vamps |
+| i7–iv7 | Dorian D'Angelo-style minor vamp |
+
+### Gospel
+| Progression | Name / notes |
+|---|---|
+| ii7–V7–I | The gospel "2-5-1", often chained: 6-2-5-1, 3-6-2-5-1 |
+| I–I7–IV | Tonicizing IV (V7/IV "amen" setup) |
+| IV–iv–I | Plagal with borrowed iv |
+| I–♯i°–ii | Chromatic passing-diminished walk-up |
+
+## 2. Substitution / variation taxonomy
+
+Progression "families" relate through a small set of transforms — these are the generation rules for variation buttons and the Builder:
+
+1. **Rotation** — any loop can start on any chord (I–V–vi–IV ≡ vi–IV–I–V). Treat loops as cyclic equivalence classes; display the rotation matching the user's tonic emphasis. (`detectRepeatingProgression` already canonicalizes rotations.)
+2. **Diatonic (function) substitution** — chords sharing two notes swap: I↔vi↔iii (tonic), IV↔ii (subdominant), V↔vii° (dominant).
+3. **Modal interchange / borrowing** — take a chord from the parallel mode: iv, ♭VI, ♭VII, ♭III, iim7♭5 in major; major IV (Dorian) in minor.
+4. **Secondary dominants** — precede any diatonic target with its V7: V/V = II7, V/vi = III7, V/IV = I7, V/ii = VI7.
+5. **Tritone substitution** — replace any dominant with the dominant a tritone away (V7 → ♭II7). Jazz flavour flag.
+6. **Backdoor dominant** — ♭VII7 resolving to I, usually as ivm7–♭VII7–I.
+7. **Quality embellishment** — same root, richer colour: triad → 7th → 9/11/13, sus2/4, add9. The main axis distinguishing genres (pop = triads/sus, jazz/neo-soul/gospel = extensions, funk = dominant 9/♯9). Already partially covered by `CHORD_SUBSTITUTIONS` in `education.js`.
+8. **Passing/approach chords** — chromatic passing diminished (I–♯i°–ii), bass-line inversions (slash chords).
+
+## 3. UX patterns worth copying
+
+- **Hookpad (Hooktheory)** — *key-relative chord palette*: only the diatonic chords of the current key, colour-coded consistently per scale degree (key-agnostic colours). Borrowed chords live in expandable secondary palettes. *Magic Chord* suggests the statistically likeliest next chord. Drag-and-drop onto a timeline. → Direct model for the Progression Builder (GOAL G3).
+- **Hooktheory TheoryTab** — progressions ranked by real-song frequency; each links to songs using it. "You're playing the Creep progression" is a strong engagement hook (partially exists via `FAMOUS_PROGRESSIONS` song lists).
+- **Scaler 2/3** — three-zone vertical flow: detection area (top) → suggested chords/scales (middle) → user-built progression (bottom). Maps directly onto this app: live detection → suggestions → builder.
+- **iReal Pro** — one-tap transposition; per-genre rendering of the same progression.
+- **ToneGym** — instant audio preview when tapping any chord/progression.
+
+## 4. Voicing data
+
+### Guitar
+Best option found: [`tombatossals/chords-db`](https://github.com/tombatossals/chords-db) (MIT, npm `@tombatossals/chords-db`, prebuilt `lib/guitar.json`):
+- All 12 keys × large suffix list, **multiple positions per chord** (open + barre + higher CAGED positions).
+- Per position: `frets` (per string, `x` = mute, low-E first), `fingers`, optional `barres`, `baseFret`. Example: `{ frets: '55775x', fingers: '114310', barres: 5 }`.
+- Companion renderer: [`tombatossals/react-chords`](https://github.com/tombatossals/react-chords) (React SVG diagrams consuming this format).
+
+Triads on string-sets (top-3 / middle-3) are *not* in chords-db but are cheap to generate: for each inversion of the triad, map the 3 chord tones onto a chosen string set within a 4-fret window. This complements the existing `GUITAR_SHAPES` in `src/lib/voicings.js`.
+
+### Piano
+No canonical open dataset exists. The sane model is **interval recipes resolved per chord quality** (the chord templates in `theory.js` already encode quality → semitone mapping):
+
+```js
+// voicing = named recipe of chord degrees, resolved per chord quality
+{
+  shell:        { LH: ['1', '7'],           RH: ['3'] },
+  rootPosition: { LH: ['1'],                RH: ['1', '3', '5', '7'] },
+  rootlessA:    { LH: ['3', '5', '7', '9'] },  // Type A: 3rd on bottom
+  rootlessB:    { LH: ['7', '9', '3', '5'] },  // Type B: 7th on bottom
+  guideTones:   { LH: ['3', '7'] },
+}
+```
+
+Conventions to encode: rootless voicings keep the top note between C4–C5; alternate Type A/B through a progression so inner voices barely move — i.e. pick the voicing minimizing semitone travel from the previous chord (simple voice-leading distance minimization).
+
+## 5. Sources
+
+- Hooktheory corpus & blog: hooktheory.com/blog/i-analyzed-the-chords-of-1300-popular-songs-for-patterns-this-is-what-i-found/ ; hooktheory.com/blog/jazz-chord-progressions/
+- 12-bar variants: en.wikipedia.org/wiki/Twelve-bar_blues ; happybluesman.com/common-variations-12-bar-blues/
+- Named progressions: en.wikipedia.org/wiki/%2750s_progression ; piano.org/chord-progressions/ ; supersimplepiano.com/learn/chord-progressions/royal-road
+- Substitutions: learnjazzstandards.com (chord substitution) ; hub.yamaha.com (beyond diatonic) ; hubguitar.com (tritone subs)
+- Gospel: gospelmaps.com/top-gospel-chord-progressions/ ; gospel.hearandplay.com (2-5-1)
+- Genre vamps: orphiq.com (reggae) ; guitar-chord.org/articles/funk.html ; orangecandymusic.com & pickupmusic.com (R&B/neo-soul)
+- Tools: producelikeapro.com (Scaler review) ; hooktheory.com/hookpad
+- Voicing data: github.com/tombatossals/chords-db ; github.com/tombatossals/react-chords ; voicinglab.com & pianowithjonny.com & thejazzpianosite.com (rootless voicings)