| name | progression-mood |
| description | Reliable techniques for darkening or brightening a chord progression — parallel-mode swaps, modal interchange (Phrygian / Aeolian / Dorian / Lydian / Mixolydian), and borrowed-chord substitutions. Use when a learner asks how to make a progression sound darker / sadder / moodier / brighter / more uplifting. |
| triggers | ["darker","darken","moodier","sadder","melancholy","minor sounding","minor-sounding","brighter","brighten","uplifting","happier","borrowed chord","borrow from","modal mixture"] |
| 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/ProgressionMoodSkill.cs (PR #71) — second canary for SKILL.md authoring","evidence-kinds":["catalog_lookup"]} |
Progression Mood — Darkening and Brightening Techniques
Use this catalog when a learner asks how to shift the mood of a progression. Pick the darken branch when the query mentions darker / sadder / moodier / melancholy / "minor sounding"; pick the brighten branch when the query mentions brighter / uplifting / happier. If both intents appear, default to darken (it's the more common ask) and offer brighten as a follow-up.
Reproduce the technique list verbatim — the choice of techniques and their ordering is pedagogically validated.
Darken branch
Open with: "Here are five reliable ways to darken a progression. Pick one or stack them — each shifts the harmonic mood without abandoning the underlying key."
- Swap to parallel minor — replace the tonic's major chord with its parallel minor (C → Cm). Pulls everything that follows toward minor-mode resolution.
- Borrow from Aeolian (natural minor) — substitute
IV → iv, V → v, and add chords from the parallel minor (bIII, bVI, bVII). Worked examples in C major:
C F G → C Fm G (the IV → iv move; standard pop-ballad).C F G → C F Gm (the V → v move; weakens the pull home).C Am F G → C Am Ab G — substitute bVI (Ab) for the original IV (F); the vi → bVI swap also works in this slot when the progression contains a vi chord.
- Borrow from Phrygian — drop in
bII (Db in C major) or use bII → I as a final resolution. The half-step approach gives a Spanish/cinematic colour.
- Borrow from Dorian — keep the
i minor but swap iv → IV (Dorian's natural 6) for the bittersweet, modal-folk feel of Scarborough Fair.
- Replace V with bVII —
C Bb F instead of C G F. Common in rock; the lack of a leading tone weakens the pull home and reads as moodier.
Close with: "Combine 1 + 2 for a strong sad-pop transformation; 3 alone for film-score gravity; 4 alone for folk melancholy."
Brighten branch
Open with: "Here are four reliable ways to brighten a progression that feels too dark or static."
- Swap to parallel major — flip a minor tonic to its parallel major (Am → A). Strongest mood-flip available.
- Borrow from Lydian — use a
IVmaj7#11 colour, or substitute the II major chord (D in C Lydian) for the diatonic ii (Dm). The Lydian raised 4th gives a floating, dreamy lift.
- Borrow from Mixolydian — add bVII as a passing chord that doesn't resolve down (
I bVII IV I); rock-anthem brightness.
- Reinforce V → I — make sure the dominant resolves cleanly back to tonic. Add a V7 or V/V to strengthen pull.
Close with: "Combine 1 + 4 for a definitive lift from minor to major; 2 alone for ethereal/cinematic brightness."
What this skill does NOT do
Do not attempt to transform a specific named progression on the fly (e.g. "darken C Am F G for me"). That requires position-by-position rewriting beyond a catalog answer — defer those queries to the LLM agent path with the catalog as background context.
Cross-reference
- C# implementation:
Common/GA.Business.ML/Agents/Skills/ProgressionMoodSkill.cs
- Tests:
Tests/Common/GA.Business.ML.Tests/Unit/ProgressionMoodSkillTests.cs
