| name | modes |
| description | Lists the seven modes of the major scale (Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, Locrian) with their scale-degree formulas and characteristic sound. Pure catalog — same fixed pedagogy whether the user asks for the whole list or a single mode. |
| triggers | ["modes of","diatonic modes","major scale modes","seven modes","what are the modes","list the modes","modal harmony","modal cadence","characteristic note","characteristic interval","ionian","dorian","phrygian","lydian","mixolydian","aeolian","locrian"] |
| license | internal |
| compatibility | {"agent-framework":">=1.0.0-preview","microsoft-extensions-ai":">=10.5.1"} |
| metadata | {"authoring-style":"deterministic-catalog","origin":"ported from Common/GA.Business.ML/Agents/Skills/ModesSkill.cs — third pure-catalog SKILL.md, joins beginner-chords and progression-mood","evidence-kinds":["catalog_lookup"]} |
The Seven Modes of the Major Scale
Reproduce the catalog below verbatim when the user asks for the modes / the diatonic modes / the modes of the major scale. When the user asks about a single mode (e.g. "what is Lydian?", "explain Phrygian"), pull just that row from the table and lead with it before optionally offering the full list.
Setup
The major scale has 7 modes. Each starts on a successive degree of the parent scale, rotating the same step pattern:
Ionian formula: W-W-H-W-W-W-H (W = whole step, H = half step)
The catalog
| # | Mode | Degrees | Characteristic note | Modal cadence | Character |
|---|
| 1 | Ionian | 1 2 3 4 5 6 7 | — (parent scale) | V → I (authentic) | Bright, the major scale itself |
| 2 | Dorian | 1 2 b3 4 5 6 b7 | natural 6 | i — IV — i (Dorian vamp; So What, Scarborough Fair) | Minor with raised 6th — jazz/folk staple |
| 3 | Phrygian | 1 b2 b3 4 5 b6 b7 | b2 | bII → i (Spanish cadence) | Dark minor with flat 2 — Spanish/flamenco |
| 4 | Lydian | 1 2 3 #4 5 6 7 | #4 | I — II — I (Lydian II vamp; the Simpsons theme) | Major with raised 4th — floating, dreamy |
| 5 | Mixolydian | 1 2 3 4 5 6 b7 | b7 | I — bVII — IV — I (rock anthem) | Major with flat 7 — bluesy/rock |
| 6 | Aeolian | 1 2 b3 4 5 b6 b7 | b6 | i — bVI — bVII — i | Natural minor |
| 7 | Locrian | 1 b2 b3 4 b5 b6 b7 | b5 (tritone w/ root) | rare; i°7 vamps with bII colour | Half-diminished — rare as a tonic |
The characteristic note is the one degree that makes the mode unique against its parallel major/minor — emphasise it in melodies and chord voicings to make the mode audible. The modal cadence column gives a vamp or progression that establishes the mode without falling back to V→I (which would imply tonal motion away from the mode).
Mnemonic
"I Don't Particularly Like Modes A Lot" — Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, Locrian.
Single-mode answer pattern
When the user asks about one mode specifically, lead with: "<Mode> is mode <n> of the major scale: degrees \<formula> — <character note>." Then optionally offer to compare with neighbouring modes (e.g. Dorian vs Aeolian for "minor flavour").
What this skill does NOT do
These are hard constraints. Do NOT answer queries in these categories from this catalog alone.
- Specific-key note enumeration (e.g. "give me the notes of D Dorian"). This catalog gives Dorian's degree formula but not the resulting notes for any particular root. Defer to the
scale-info skill or the broader LLM agent path. Do NOT output specific-key note lists from this catalog alone.
- Non-diatonic modes (harmonic minor modes, melodic minor modes, modes of limited transposition). This catalog covers only the seven modes of the major (a.k.a. diatonic) scale. If asked, decline cleanly: "This catalog only covers the diatonic modes; harmonic-minor modes and others would need different tooling."
- Open-ended composition recommendation ("what mode should I use for an angry feel?"). The characteristic-note + modal-cadence columns give a pro player concrete scaffolding (e.g. "Phrygian b2 + bII→i for Spanish/cinematic dread"), but mood-mapping a mode to an unstated emotion is subjective — emit the catalog data and the cadence pattern, then let the broader agent path reason about fit. Do NOT claim a single "right" mode for a feeling.
Cross-reference
- C# implementation:
Common/GA.Business.ML/Agents/Skills/ModesSkill.cs (regex-driven, kept as deterministic fast path)
- Tests:
Tests/Common/GA.Business.ML.Tests/Unit/ModesSkillTests.cs
