# Jp Modulation

> 50 modulation techniques - achieve modulation in any direction (up/down a half step, whole step, or minor 3rd; parallel key; chained modulations) using V7 cushions, ura-code (tritone substitution), two-five chains, dim/aug chords, parallel shifts, and more. Use when the user wants to modulate within a song (e.g., raising the key for the final chorus, a surprise key change in the D-melo/bridge), or wants to know how to transition smoothly from key X to key Y.

- Skill: `jtydhr88/jp-modulation` (Agent Skill)
- Install (CLI): `npx skillmds@latest add jtydhr88/jp-modulation`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jtydhr88/jp-modulation/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: jtydhr88 (https://skillmd.com/u/jtydhr88)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/jtydhr88/jp-modulation

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# 50 Modulation Techniques (転調テクニック50)

Source: Luna Umegaki (梅垣ルナ), *Tenchō Technique 50 — A Practical Collection of Chord Progressions That Expand Your Imagination* (転調テクニック50 ―イマジネーションが広がる実践的コード進行集, Rittor Music, 2017).
The book contains 50 modulation examples. The home key is always Key=C or Key=Am; degree-name (ディグリー・ネーム, Roman numeral) thinking makes every example portable to any key.

## 1. Modulation Fundamentals

### 1.1 Closely Related Keys and Distant Keys

There are 24 commonly used keys (12 major + 12 minor). Taking Key=C as an example, the six types of **closely related keys** (近親調):

| Relationship | Example (home key C) | Character |
|---|---|---|
| Parallel key (同主調, same tonic) | C ↔ Cm | Major/minor sharing the same tonic; light/dark contrast can be pulled very hard |
| Relative key (平行調 — note: in Japanese this means the *relative* major/minor, not "parallel" in the English sense) | C ↔ Am | Same key signature, nearly all chords shared; changes the mood with a light touch |
| Dominant key (属調, perfect 5th up) | C → G | Scales differ by only 1 note, many common chords, the smoothest modulation |
| Relative key of the dominant (属調の平行調) | C → Em | Same key signature as G |
| Subdominant key (下属調, perfect 5th down) | C → F | Symmetric with the dominant key, equally smooth |
| Relative key of the subdominant (下属調の平行調) | C → Dm | Same key signature as F |

**Distant keys** (遠隔調): every key beyond the above. The atmosphere changes drastically; used well, this creates dramatic (ドラマチック) development. Half-step and tritone relationships both belong here.

### 1.2 Core Concept: The Cushion Chord (クッション)

A transitional chord that makes the modulation sound smooth. **Most common = the V or V7 of the target key**, inserted in the last 1–2 beats before the modulation, resolving across the barline as V7→I (ドミナント・モーション, dominant motion). In the home key this V7 is usually a non-diatonic chord (III7, IV7, VI7, etc.) — exactly the "color-change" signal.

The cushion chord's **announcement ladder** (how loudly it says "I'm about to modulate!"):
- **V** (triad): smoothest, lowest announcement
- **V7**: contains the tritone (トライトーン), more thrust
- **♭II7 (ura-code, 裏コード — tritone substitution)**: injects foreign notes, strongest announcement, with built-in jazzy flair
- **dim / aug** (stand-ins for V7(♭9)/V7(♭13)): distinctive sonority, maximum impact
- **IV(onV)-type on-chord** (オン・コード, slash chord, e.g. F/G): no 3rd (leading tone) → tonal sense blurred → paradoxically "free to fly to any key"

### 1.3 Degree Thinking and the Three Tools of Unity

- Think of every chord as a Roman-numeral degree: the key changes but the degrees don't — just ask "**which chord is the V7 of the target key?**"
- Three tools for keeping a sense of unity across the modulation:
  1. **Shift the same progression wholesale** (identical progression transposed; degrees stay exactly the same)
  2. A **cliché line** (クリシェ — bass/inner-voice/top-voice line moving stepwise by half steps) running through both keys
  3. A **common tone as the top note** (トップ・ノート), letting the melody carry through the modulation

### 1.4 Modulation Distance Determines Character (Quick Reference)

| Direction | Character |
|---|---|
| Half step up | Standard key-lift before the outro, emotional uplift |
| Half step down | Distant-key jolt, yet requires no special technique |
| Whole step up | Surging; more tragic-heroic when passing through a dim chord |
| Whole step down | Neighboring key; naturally beautiful "finale feel" / weight |
| Minor 3rd up | Major = splendid and grand; minor = subtle color change |
| Minor 3rd down | Major = bright yet settled; positive and refreshing |
| Parallel key (同主調) | Direct light/dark switch (contrast) or gradual shading |
| Relative key (平行調) | The smoothest light/dark switch |
| Dominant/subdominant key | Many common chords, smoothest of all |
| Tritone | Farthest distance; bridged well, it is the most dramatic |

### 1.5 Practical Decision Flow (How to Choose a Technique)

1. **Fix the target key and direction**: decide where you want to go (key-lift for the chorus? light/dark switch? final-stretch climax?), and compute the interval relationship (half step / whole step / minor 3rd…).
2. **Look up the direction index in Chapter 2**: find the techniques for that direction and pick by desired "announcement level" (smooth ↔ impactful).
3. **Compute the target key's V7**: this is the universal cushion; for more style swap in the ura-code (裏コード, tritone substitution, ♭II7); for more impact use the dim/aug stand-in; for stealth use the IV(onV)-type on-chord.
4. **Choose a unity strategy**: shift an identical progression wholesale? Run a cliché line through? Keep a common tone on top? (Pick one or combine.)
5. **Place the landing**: put the cushion chord in the last 1–2 beats before the modulation, resolving across the barline to the new key's I (or a IIm7/IVm two-five entry point).
6. **Plan the return trip**: turn the new key's I into a dominant 7th (I→I7) or into the home key's IIm, and ride a secondary dominant / two-five-one back home (see Techniques 13 and 14).

### 1.6 Common Scenarios → Recommended Techniques

| Scenario | Recommended techniques |
|---|---|
| Whole-chorus key lift (standard before the outro) | 10 (half step up, V7 cushion), 15 (V7 half-step shift), 41 (through a dim, more tragic-heroic) |
| One last explosion in the ōsabi (大サビ, final climactic chorus) | 15 (half step up), 09 (whole step down for reverse weight), 21 (secondary-dominant ura-code push to the finish) |
| Verse → chorus opening up (dark → bright) | 05, 12, 17, 23, 36, 39 |
| Bright A/B sections → suddenly profound chorus (bright → dark) | 16, 30, 34, 40 |
| Outro finale feel / splendid ending | 02, 08, 24, 31, 33, 43 |
| Interlude/solo section world-change | 27, 40 |
| Intro vs. A section in contrasting keys | 30, 35, 45, 48 |
| Stylish jazzy flavor (おしゃれ) | 20, 21, 49 |
| Gradual light/dark shading without abruptness | 36, 37 |
| Multi-key journey / splendid chorus progression | 44, 47, 50 |

---

## 2. Index by Target Direction

### 2.1 Half Step Up (minor 2nd up)

*Character: a distant-key jolt plus emotional uplift; the classic pop-music "final-chorus half-step key lift" direction.*

**Technique 10 | C → D♭** (Track 10)
- `C F | Dm7 G7 | C F | C A♭7 || D♭ G♭ | A♭ D♭ | G♭ A♭ | D♭` (A♭7 = target key's V7)
- Point: the V7 cushion works just as well for a half step up; this example deliberately **changes the progression** after the modulation (plain → splendid) for a fully refreshed mood.
- Scenario: chorus key lift near the end of the song (pop-music standard).

**Technique 15 | Am → B♭m** (Track 15)
- Identical progression `Im | IVm | IIm7(♭5) | V7` shifted up a half step; key move: bar 4's E7 (V7 of Am) → **shift up a half step to F7** (V7 of B♭m); after the V7→V7 parallel move, F7–B♭m resolves.
- Scenario: the ōsabi (大サビ, final climactic chorus) — the same chorus lifted a half step to "explode one last time."

**Technique 30 | C → C♯m** (Track 30)
- `C | Em | Dm | G G♯ || C♯m | A | F♯m7 G♯m7 | C♯sus4 C♯m`; after the two-five (Dm–G), G **shifts up a half step** to G♯ = V of C♯m.
- Point: the two keys share **no common chords at all** → an extremely strong "we modulated!" sensation; a cheerful major key flips instantly into a profound minor.
- Scenario: major-key intro, A section turning minor — vivid contrast.

### 2.2 Half Step Down (minor 2nd down)

*Character: also a distant key; the mood changes abruptly but more calmly than a key lift — good for quietly recoloring between sections.*

**Technique 04 | Am → G♯m** (Track 04)
- `Am7 | D7(9) | Bm7 E7(♭9) | Am7` (`Im7 | IV7(9) | IIm7 V7(♭9) | Im7`), the identical progression shifted down a half step; Im drops straight onto the new key's Im.
- Point: the half-step relationship is a distant key, so the mood-jolt is strong — yet no special technique is needed.
- Scenario: modulating between A-melo (Aメロ, verse) and B-melo (Bメロ, pre-chorus), or following the chorus with a different progression to create a drop-off.

**Technique 29 | C → B** (Track 29)
- `C | Em | Dm | G F♯ || B | D♯m7 | E F♯ | B`; after the two-five (Dm–G), G **shifts down a half step** to F♯ = V of B, then V–I.
- Scenario: colorful development while preserving a calm character (A/B section → chorus).

**Technique 39 | Am → A♭** (Track 39)
- `Am A♭aug | C(onG) F♯m7(♭5) | F△7 Em7 | G(onA) A || A♭ …`; at the resolution point, **Im is replaced by the major I (A)**, and A is a **half-step neighbor** of the new key's I (A♭), suppressing any abruptness.
- Point: both halves share the same descending chromatic bass cliché line (A→A♭→G→F♯… / A♭→G→G♭→F…) for unity.
- Scenario: expansive modulation from minor A/B sections into a bright chorus.

### 2.3 Whole Step Up (major 2nd up)

*Character: an unmistakable surge; on-chords or a passing dim let you dial the impact up or down.*

**Technique 14 | C → D** (Track 14)
- `F G | C A7 || D | G | Em A7 | D`; A7 = home key's VI7 = **V7 of D** as the cushion.
- Point: to return to C, change the final D to **Dm** (IIm of C) and continue G–C, forming a 2-5-1 homecoming.
- Scenario: C section serving as A/B, D section as chorus — a natural opening-up.

**Technique 26 | C → D** (Track 26)
- `F△7 | Em7 | Dm7 | F(onG) G(onA) | D△7 …`; F(onG) = a revoicing of G7(9,11) with the 3rd and 5th removed — **no 3rd → blurred tonality** — then **shifted up a whole step** to G(onA) (= a revoicing of A7(9,11)) landing on D△7.
- Scenario: on-chord modulation is exceptionally beautiful; B section → majestic chorus.

**Technique 31 | Am → B** (Track 31)
- `Am A♭aug | C(onG) F♯m7(♭5) | Dm7 | F6(onG) F♯ || B …`; `Dm7–F6(onG)` = a two-five borrowed from the relative key C, then a **half-step move** to F♯ (V of B).
- Point: the underlying G7 of F6(onG), seen from the key of F♯, is the ura-code (裏コード, tritone substitution) — back-to-back dominant function; the bass descends chromatically on both sides (sinking → grandeur).
- Scenario: song-ending chorus → outro, "one more layer" of grand climax.

**Technique 41 | Am → Bm** (Track 41)
- Identical progression shifted up a whole step; at the seam, `Am → A♯dim → Bm` moves chromatically = **passing diminished** (パッシング・ディミニッシュ); A♯dim ≈ F♯7(♭9) minus its root = a stand-in for Bm's V7.
- Scenario: final-stretch chorus key lift — emotions surge, the minor-key tragic-heroic feel deepens further.

### 2.4 Whole Step Down (major 2nd down)

*Character: neighboring key, naturally beautiful; combines "finale feel" with weight.*

**Technique 08 | C → B♭** (Track 08)
- `C | Em7 | Dm7 | G7 F7 || B♭ F(onA) | Gm Fm7 B♭7 | E♭ | F7 | B♭`; F7 (home key's IV7) = **V7 of B♭**. This is where the book's term "cushion" (クッション) is first defined.
- Point: modulating to a neighboring key is not abrupt, yet the mood clearly changes; after the modulation, the stepwise bass B♭→A→G plus a borrowed two-five add thickness.
- Scenario: pushing the outro toward a climax, creating a "grand finale" atmosphere.

**Technique 09 | Am → Gm** (Track 09)
- Loop `Im | IVm | IIm7(♭5) V7 | Im IV7(=D7) || Gm …`; D7 = V7-of-Gm cushion, then the same melody and progression shift down a whole step wholesale.
- Point: whole step down in minor = a handy device for "manufacturing a surge the easy way."
- Scenario: in the final stretch, repeat the same chorus shifted down a whole step for a stronger jolt to the listener.

**Technique 24 | C → B♭m** (Track 24)
- `… C | C7 F7 || B♭m Aaug B♭m(onA♭) E♭(onG) | G♭△7 | Fm7 | B♭m`; C7 (new key's II7 = **double dominant**, ドッペル・ドミナント) → F7 (V7) → B♭m = `II7–V7–Im` two-five-one; **two dominant 7ths in a row** double the modulation feel.
- Point: after the modulation the bass B♭–A–A♭–G forms a minor cliché line, sinking and weighty.
- Scenario: a heavy passage that makes people go "look up! listen!".

### 2.5 Minor 3rd Up

*Character: in major = splendid and grand (華やか); in minor = a discreet color change that doesn't call attention to itself.*

**Technique 01 | Am → Cm** (Track 01)
- `Am | A♭aug | C(onG) | F♯m7(♭5) | F△7 Em7 | Am`, the identical progression moved up a minor 3rd for the Cm section.
- Point: the descending chromatic bass cliché line (A→A♭→G→F♯→F→E / C→B→B♭→A→A♭→G) runs through both keys, and the top notes keep the same intervallic relationship.
- Scenario: in minor, when you want "a slight recolor without upheaval" — the verse develops naturally while leaving the expectation that "there's more to come."

**Technique 03 | C → E♭** (Track 03)
- `Dm7(9,11) | G7(13) | Em7 | Am7 || Fm7(9) | B♭7(13) | E♭△7`; **every chord keeps the note G fixed as the top note** (serving in turn as 11th/root/3rd/7th/9th/13th/3rd), landing via the new key's two-five-one.
- Scenario: a common tone carrying the melody through — the "monotonous melody" becomes the personality.

**Technique 07 | C → E♭** (Track 07)
- `C | Dm | G7 | C B♭7 || E♭ | Gm7 | A♭ B♭ | E♭`; B♭7 = V7-of-E♭ cushion.
- Point: minor 3rd up between major keys = **hanayaka** (華やか, splendid and grand) — the counterpart to the "settled" character of the minor 3rd down.
- Scenario: last run of the chorus → pushing the outro to a climax.

**Technique 27 | C → E♭m** (Track 27)
- `C | Em7 | F | C G(onB) | Am | D7 | F6(onG) || A♭m7 B♭m7 | E♭m …`; F6(onG) (≈ G7sus4 — no 3rd, no tritone → weak resolution pull) slides directly to the **half-step neighbor** A♭m7 = IVm7 of E♭m, then `IVm7–Vm7–Im`.
- Scenario: a cute C-major verse → a solemn E♭m interlude, backing a guitar/piano solo.

### 2.6 Minor 3rd Down

*Character: stays bright while gaining a little composure; a positive, refreshing direction.*

**Technique 02 | C → A** (Track 02)
- Canon progression (カノン進行) `C G | Am Em | F C | F G || A E | F♯m C♯m | D A | D E | A`, shifted down wholesale with degrees exactly identical.
- Point: the ending F–G–**A** replaces F–G–C; A is the parallel key of Am (C's relative minor), so the dissonance is minimal.
- Scenario: major-key Canon in the chorus, outro moved down a minor 3rd — a splendid ending within unity.

**Technique 06 | C → A** (Track 06)
- `C | F | G7 | C E7 || A E(onG♯) | F♯m7 C♯m | D E7 | A`; E7 = home key's III7 = **V7-of-A** cushion (V7–I is the most frequent move in the whole book).
- Point: minor 3rd down between major keys = "stay bright, settle slightly"; after the modulation comes a shortened reharmonization of the Canon progression (bass A→G♯→F♯…).
- Scenario: verse → chorus, with an "eyes light up" moment at the modulation.

**Technique 28 | Am → F♯** (Track 28)
- `Am | Em(onG) | F△7 Em7 | Dm7 G | C C♯ || F♯ …`; C (Am's ♭III, tonic-function substitute) **shifts up a half step in parallel** to C♯ = V of F♯, then V–I.
- Point: this chapter's mantra — "make a half-step parallel move onto the cushion chord"; the first half's stepwise descending bass is stately and grand.
- Scenario: cold, austere minor B section → splendid major chorus; a total mid-song change of character.

**Technique 35 | Am → F♯m** (Track 35)
- `Am F△7 G | Em7` (×2); on the second pass, Em7 **shifts up a whole step** to F♯m7 = the new key's Im7, entering directly.
- Point: **the whole-step parallel move sounds remarkably beautiful**; Am→F♯m = "the relative key of parallel-key A" direction — fresh but not jarring.
- Scenario: intro → A section, announcing a change of character in an instant, deepening the minor key's gloomy haze.

### 2.7 Major 3rd Up / Down

*Character: a fairly distant leap; create surprise via half-step shifts, identical progressions, or a cushion-free direct jump.*

**Technique 33 | Am → D♭ (major 3rd up)** (Track 33)
- `Am G6 | F△7 Em7 | Dm7 G | Em7 || E♭m7 A♭7 | D♭△7 …`; Em7 **shifts down a half step** to E♭m7 = IIm7 of D♭, flowing straight into the two-five-one `E♭m7–A♭7–D♭△7`.
- Point: "half-step shift → resolve to the new key's I via a two-five-one" is a must-memorize formula.
- Scenario: post-chorus final-stretch modulation into the ending, pushing to a climax before closing.

**Technique 38 | Am → C♯m (major 3rd up)** (Track 38)
- `Bm7(♭5) E7 | Am | F♯m7(♭5) | F△7 Em7 | Asus4 Am || D♯m7(♭5) G♯7 | C♯m …` (both halves exactly identical in shape).
- Point: in minor, **Im is an extremely flexible resolution point** — after resolving on Im, going to almost any key causes little dissonance; dive straight into the new key's IIm7(♭5) to launch an identical minor two-five-one, "melancholy accelerating."
- Scenario: when the whole chorus repeats as the ending, turn it into a modulating repeat.

**Technique 32 | Am → Fm (major 3rd down)** (Track 32)
- The Autumn Leaves progression (枯葉進行) `IVm ♭VII | ♭III△7 ♭VI△7 | IIm7(♭5) V | Im` moved wholesale to Fm; at the seam: after Am resolves, **shift up a half step** to B♭m = the **IVm** of Fm (the first chord of the new key's progression).
- Point: the landing spot of a half-step shift **is not limited to V** — always keep the "shift to something other than V" perspective in stock.
- Scenario: deepening a sorrowful loop even further.

**Technique 34 | C → G♯m (major 3rd down)** (Track 34)
- Reharmonized Canon `C G | Am Gm7 C7 | F Em7 Am | Dm G7 || G♯m …`; G7 → **G♯m a half step above, taken directly as the new key's Im**, jumping without any cushion.
- Point: no cushion = maximum "it suddenly changed!" impact.
- Scenario: a dramatic form where A/B sections stay bright and the chorus turns suddenly profound and heavy.

### 2.8 Fourth/Fifth Relationships (dominant/subdominant-key directions)

*Character: the most common chords and the smoothest direction; home turf of the secondary dominant (セカンダリー・ドミナント).*

**Technique 11 | C → F (subdominant key)** (Track 11)
- `C | Dm | G7 | C7 || F | B♭ | C7 | F`; C7 = home key's I7 = F's **secondary dominant** and simultaneously the target key's V7 — one stone, two birds.
- Point: the subdominant key shares many chords, so the modulation is smooth; the moment a secondary dominant sounds, listeners sense "something's about to unfold!"
- Scenario: stoking anticipation at the A-section → B-section seam.

**Technique 12 | Am → F (relative key of the subdominant)** (Track 12)
- `Am | Dm | G | C7 || F C(onE) | Dm Am(onC) | B♭ C7 | F`; after the minor-key staple Im–IVm–♭VII, C7 = the secondary dominant of ♭VI (F).
- Point: C7 can be softened to C (weaker announcement); if the modulation feels too faint, densify the harmonic rhythm after the modulation (a change every 2 beats) to make it explicit.
- Scenario: minor → gentle major (the bass F–E–D–C–B♭ descends stepwise, splendid and fluid).

**Technique 13 | C → G (dominant key)** (Track 13)
- `Dm | G7 | C | D7 || G | C | D7 | G`; D7 = home key's II7 secondary dominant = V7 of G.
- Point: the dominant key shares many chords and flows easily; to return to C, change the final G to **G7** as a cushion and continue `C F G C`.
- Scenario: a demonstration that secondary dominants are usable everywhere.

**Technique 20 | C → F (subdominant key)** (Track 20)
- `C | F | G7 | C F♯7 || F …`; use **F♯7, the ura-code (裏コード, tritone substitution) of the target key's V7 (C7)**, as the cushion — more stylish, with more contour.
- Point: announcement level V < V7 < ♭II7; F♯7 can also be read as "ura-code-ification of the secondary dominant."
- Scenario: any seam — A→B, into the chorus — whenever "something's missing," try it.

**Technique 21 | Am → Dm (subdominant key)** (Track 21)
- Two **exactly identical** minor progressions joined; the straightforward move is Dm's secondary dominant A7, here replaced by its ura-code **E♭7** — the root motion E♭→D descends by half step, a beautiful line.
- Point: the ura-code of a secondary dominant has an extremely high announcement level — "something new is coming!"
- Scenario: pushing the chorus higher in the final stretch and closing memorably.

**Technique 23 | Am → G (relative key of the dominant)** (Track 23)
- `Am | Dm | E | Am D || G | C | Am7 D7 | G`; bars 4–5's Am–D–G = the key of G's **IIm–V–I** (ツー・ファイブ・ワン, two-five-one).
- Point: before the target I, first place V (D); before V, place IIm (Am) — building the bridge layer by layer.
- Scenario: minor → major "the view opens up," especially verse → chorus.

**Technique 25 | Am → Em (dominant key)** (Track 25)
- `E | Am | Dm | G | E | Am | F♯m7(♭5) B7 || Em …`; `F♯m7(♭5)–B7–Em` = the **minor two-five-one IIm7(♭5)–V7–Im**.
- Point: F♯m7(♭5) is simultaneously the VIm7(♭5) diatonic to the Am **melodic minor** scale = a **pivot chord** (ピボット・コード).
- Scenario: two-part A-section → chorus form, suits acoustic arrangements.

**Technique 36 | Am → E (perfect 5th up)** (Track 36)
- `… F△7 Em7 | G(onA) A B || E …`; A = Im turned major = **IV of E**, B = V of E → sandwiching IV before the new key's I forms **IV–V–I**.
- Point: tonal "gradation" (グラデーション) — like a color gradient, hints of the major key seep through bit by bit.
- Scenario: sentimental minor B section → warm major chorus, with clear tension and release.

**Technique 40 | C → Fm (perfect 4th up)** (Track 40)
- `Dm G | Em7 Am7 | Dm7 G | C Edim || Fm …`; **Edim = a stand-in for Fm's V7 (C7)**: its notes ≈ C7(♭9) minus the root (E=3rd, G=5th, B♭=7th, D♭=♭9th).
- Point: compared to plain C7, the shadowed dim announces more loudly "we're heading into minor!" — the worldview changes abruptly.
- Scenario: B section wavering → chorus release, "the decision is made!"

**Technique 42 | C → F (subdominant key)** (Track 42)
- `F△7 G(onF) | Em7 A7 | Dm G7 | C Caug || F …`; **Caug as the cushion** (compare its notes to C7(♭13): C/E/G♯), containing an ascending chromatic cliché line **G→G♯→A** pushing toward F.
- Point: C7 would also modulate, but the aug sonority hits harder, making the listener strongly anticipate a new development.
- Scenario: restrained verse vs. a grandly unfolding chorus (slow the harmonic rhythm before the modulation).

**Technique 43 | C → Dm (relative key of the subdominant)** (Track 43)
- `C G(onB) | C(onB♭) F(onA) | Dm7 | F6(onG) Aaug || Am7(onD) …`; the bass descends C→B→B♭→A, `Dm7–F6(onG)` = a two-five (F6(onG) ≈ G7), and **Aaug ≈ A7(♭13) = a stand-in for Dm's V7**.
- Scenario: final chorus in C → a slightly "cool" Dm ending, closing on light/dark contrast.

### 2.9 Parallel Key (同主調 — light/dark switching)

*Character: the tonic stays put while light and dark swap directly; sharing the same V7 is the greatest convenience.*

**Technique 16 | C → Cm (bright → dark, direct contrast)** (Track 16)
- `F△7 | Em7 Am7 | Dm7 | Dm7(onG) G7 || Cm | Fm | Dm7(♭5) G7 | Cm`.
- Point: **G7 is the V7 in both keys** (parallel major and minor share the dominant) — one chord, two jobs; "bright → dark" with zero friction.
- Scenario: major A/B sections, minor chorus — crisp merihari (メリハリ, dynamic contrast).

**Technique 17 | Am → A (dark → bright)** (Track 17)
- `Am | G♯dim | Am(onG) | F♯m7(♭5) | F△7 | Em7 | Dm | E7 || A E(onG♯) | A(onG) | D(onF♯) | Dm(onF) | E7 | A`.
- Point: **E7 is the shared V7 of both keys**; before and after the modulation the bass is the same descending chromatic cliché line (A–G♯–G–F♯–F–E), and the matching contour preserves unity.
- Scenario: lonely minor A section, major chorus opening wide — matching an emotional reversal in the lyrics.

**Technique 37 | C → Cm (gradation style)** (Track 37)
- `C C7 | F D(onF♯) | C(onG) Am | Fm G7 || Cm A♭ | Fm G7 | Cm …`; **Fm = the subdominant minor** (サブドミナント・マイナー, IVm — a faintly overcast color) → `IVm–V7–Im` flows smoothly into Cm.
- Point: in contrast to Technique 16's "direct switch," here light shades into dark **gradually** — "like a gradient filter"; i.e., "use the target key's IVm–V7 as the cushion."
- Scenario: bright A section, slightly darker B section — a smooth change of mood.

### 2.10 Relative Key (平行調 — relative major/minor)

*Character: same key signature, nearly all chords in common; the smoothest light/dark switch.*

**Technique 05 | Am → C** (Track 05)
- `Am | Dm | E7 | Am G || C G(onB) | Am Em | F G7 | C`; G = home key's ♭VII = **the target key's V** as cushion; G–C is simply V–I.
- Point: the origin of the book's whole "cushion" idea; after the modulation comes a shortened reharmonization of the Canon progression (bass C→B→A→E→F→G→C).
- Scenario: minor A section (shadow) → major chorus (light), "the view suddenly opens up."

### 2.11 Distant Keys (tritone relationship)

*Character: the farthest key relationship; bridge it with the ura-code and you get the most dramatic development of all.*

**Technique 18 | C → G♭ (diminished 5th up)** (Track 18)
- `C G(onB) Am | Gm7 C7 | F C(onE) Dm7 | Dm7(onG) D♭7 || G♭ …`; **D♭7 = C's ♭II7 (ura-code) = G♭'s V7** — a dominant function shared by both keys serves as the bridge.
- Point: the first half's bass descends stepwise C–B–A–G–F–E–D–(G)–D♭; C and G♭ are the most distant of keys, so bridged well, the effect is supremely dramatic.
- Scenario: dramatic development requiring maximum contrast.

**Technique 19 | Am → E♭m (diminished 5th up)** (Track 19)
- `Am | Dm | G7 | C△7 | F△7 | Em7 | Am | B♭7 || E♭m …`; B♭7 = the ura-code of Am's V7 (E7) = E♭m's V7 — the formal definition of the **pivot chord** (ピボット・コード: a chord that has an identity in both keys).
- Scenario: B section → chorus in one sweep; used at the ending it also closes dramatically.

### 2.12 Chained Modulations (連続転調)

*The only rule: there is no rule saying "one modulation per song" — as long as the music holds together, modulate as many times as you like.*

**Technique 22 | Am → A♭ → E♭ (half step down → its dominant key)** (Track 22)
- `Am | Em7 | F | C | Dm | Bm7 E7 A7 || A♭△7 | D♭△7 | Gm7(♭5) | C7 | Fm | B♭7 | E♭△7`; A7 = the **ura-code** of A♭△7's secondary dominant (E♭7).
- Point: after the modulation, `I△7–IV△7–VIIm7(♭5)–III7–VIm–II7` is a **strong progression** (強進行, roots falling by consecutive 5ths); the closing `Fm–B♭7–E♭△7` two-five-one carries out the second modulation in stride.
- Scenario: a wistful, tightly-wound B section → a chorus that unfurls in splendor in an instant.

**Technique 44 | C → (hidden F) → E (major 3rd up)** (Track 44)
- `C | Gm7 C7 | F△7 | F△7 || F♯m7(♭5) | B7(♯9) B7(♭9) | E△7`; the first half's `Gm7–C7–F△7` is simultaneously a **two-five-one in Key=F** (F lurking inside); the second half is a modified two-five-one (IIm7(♭5) borrowed from the parallel key Em + an altered dominant 7th).
- Scenario: chained major-key modulations, splendid — well suited to chorus progressions.

**Technique 45 | C → A → F♯m (minor 3rd down ×2)** (Track 45)
- `C△7 | Dm7 | B♭△7 | A△7 | D△7 | F(onG) G7 | F♯m7(9)`; B♭△7 **shares 3 notes** with Dm7 (D, F, A) as the cushion, then slides down a half step into A; G7 = the **ura-code** of F♯m's V7 (C♯7), preceded by its revoicing F(onG).
- Point: short-span chained modulations that keep delaying resolution = the emotion of "hazy irresolution."
- Scenario: the A section straight out of the intro and other song-opening passages, deliberately projecting a "complex" impression.

**Technique 46 | C → Em → G (relative key of the dominant → relative key)** (Track 46)
- `C△7 E♭7(9) | Dm7(11) | G7 | Em7 A7(♭9) | Dm7 | G7(13) || Em E♭aug | Em7(onD) C♯m7(♭5) | C△7 | Am7(onD) G`.
- Point: Em = C's **tonic-function substitute chord** (a common/pivot entry with no friction); the Em section's bass cliché line E–E♭–D–C♯; C△7 has a double identity (Em's ♭VI△7 = G's IV△7); Am7(onD) = a softened revoicing of D7 closing V–I. **The top note is unified on the common tone G.**
- Scenario: when crossing multiple keys, build the melody first from tones common to all the chords.

**Technique 47 | C → Em → E → G → Em (two-five chain)** (Track 47)
- `Dm7 G7 | Em7 A7 | F♯m7(♭5) B7 | E△7(9) E7(♭9) | Am7 D7(9) | G△7 C△7(9) | F♯m7(♭5) B7 | Em`.
- Point: one two-five per bar drives it forward; the highlight is a **minor two-five (F♯m7(♭5)–B7) resolving to the parallel major's I (E△7(9))** — strong surprise; then I△7→I7(♭9) becomes a dominant 7th to keep pushing, closing at last with a minor two-five-one.
- Scenario: maximum impact (インパクト) — best suited to the chorus.

**Technique 48 | Am → Gm → Bm (whole step down → major 3rd up)** (Track 48)
- `Am7 | D(onE) | Cm7 | F(onG) | Em7 | F♯7 | A(onB)`; **every modulation seam uses an on-chord**: D(onE) = E7(9,11) minus the 3rd and 5th, F(onG) = Gm7(9,11) minus the 3rd and 5th.
- Point: no 3rd (leading tone) → blurred tonal sense → the ear glides smoothly into the new key; a plain dominant would actually be more jarring.
- Scenario: intro and A section in different keys, with vividly contrasting melodies.

**Technique 49 | C → Cm → B♭m → A♭ → F (two-five reharmonization chain)** (Track 49)
- `Dm7 | F△7(onG) D♭7(9) | Cm7(9) | E♭(onF) C♭7(9) | B♭m7(9) | D♭(onE♭) G♭7 | F△7`.
- Point: a triple chain of the module "IIm7 → (V7 as on-chord) → (V7's ura-code) → new key's Im7 (**doubling as the next key's IIm7**)" — every landing point is both a resolution and the start of the next two-five; the final G♭7 (ura-code of F's V7) resolves down a half step to F△7.
- Scenario: 2-5-1 reharmonization (リハーモナイズ) = an extremely stylish (おしゃれ) chained-modulation atmosphere.

**Technique 50 | C → D → E → G → A → B (I△7 parallel motion)** (Track 50)
- `C△7 | D△7 | E△7 | E△7 | G△7 | A△7 | B△7 | B△7` — every chord is the **I△7** of its own key; whole step ×4 + minor 3rd ×1 in continuous parallel motion through 6 keys.
- Point: parallel-moving major 7th chords = voice relationships fully preserved; short hops are seamless, and even the far leap "lands beautifully" (美しくキマる).
- Scenario: a bright, refreshing (さわやか) all-purpose modulation template.

---

## 3. Index by Technique Type

### 3.1 V7 Cushion Family (basic cushion forms)

Core question: **"Which chord is the target key's V7?"** — place it in the last 1–2 beats before the modulation, landing V7→I across the barline.
- **05** Am→C: the target key's V (G, home key's ♭VII) as cushion — the origin of the cushion idea
- **06** C→A: E7 (home key's III7) = new key's V7, bright yet settled
- **07** C→E♭: B♭7 = new key's V7, a splendid minor-3rd-up push
- **08** C→B♭: F7 (home key's IV7) = new key's V7 — where the term "cushion" is defined
- **09** Am→Gm: D7 (home key's IV7) = new key's V7 + identical progression down a whole step
- **10** C→D♭: A♭7 = new key's V7, with a deliberate change of progression after the modulation
- **11** C→F: C7 (home key's I7) = F's secondary dominant and new key's V7 — one stone, two birds
- **12** Am→F: C7 = secondary dominant of ♭VI (F); if the announcement is too weak, densify the harmonic rhythm after modulating
- **13** C→G: D7 (home key's II7 secondary dominant) = new key's V7; for the return trip just change G to G7
- **14** C→D: A7 (home key's VI7) = new key's V7; to return, change D to Dm and continue G–C
- **15** Am→B♭m: E7→F7, **V7→V7 half-step parallel move** — the ōsabi weapon
- **16** C→Cm: G7 is the **shared V7 of both keys**, one chord doing two jobs for a direct light/dark switch
- **17** Am→A: E7 shared by both keys + the same cliché line in both keys for unity
- **36** Am→E: sandwich the new key's IV (A) before its V (B) = **IV–V–I gradation-style** landing
- **37** C→Cm: the **target key's IVm–V7** as cushion (subdominant-minor gradation)

### 3.2 Ura-Code Family (tritone substitution, ♭II7)

Principle: ♭II7 shares the same tritone as V7, so its resolving function is equivalent; the bass resolves down a half step — stylish, and the loudest announcement.
- **18** C→G♭: D♭7 = home key's ♭II7 = target key's V7, dual dominant function bridging distant keys (major version)
- **19** Am→E♭m: B♭7 = ura of home key's V7 = target key's V7 — the pivot chord (minor version)
- **20** C→F: cushion with **F♯7, the ura-code of the target key's V7 (C7)** — more stylish than V7
- **21** Am→Dm: **secondary dominant A7 replaced by its ura-code E♭7**, root E♭→D descending by half step
- **22** Am→A♭: A7 = ura-code of the target opening chord A♭△7's secondary dominant (E♭7)
- **31** Am→B: F6(onG) (a G7 revoicing) is the ura-code seen from F♯ → dominant functions back to back
- **45** A→F♯m: G7 = ura-code of F♯m's V7 (C♯7), preceded by its revoicing F(onG)
- **49** three ura-codes in the chain: D♭7(9), C♭7(9), G♭7 — all resolving down a half step

### 3.3 Two-Five Family (ツー・ファイブ)

- **03** C→E♭: land via the new key's borrowed IIm7–V7 (Fm7(9)–B♭7(13)–E♭△7)
- **23** Am→G: build up layer by layer before the target I — Am–D–G = new key's IIm–V–I
- **24** C→B♭m: C7–F7–B♭m = **II7–V7–Im** (double-dominant, ドッペル・ドミナント, back to back)
- **25** Am→Em: minor two-five-one IIm7(♭5)–V7–Im + a melodic-minor pivot chord
- **29** C→B: after the two-five (Dm–G), V **shifts down a half step** to become the new key's V
- **30** C→C♯m: after the two-five, V **shifts up a half step** to become the new key's V — light/dark reversal
- **31** Am→B: on-chord two-five (Dm7–F6(onG)) + half-step move
- **33** Am→D♭: Em7 shifts down a half step to become the new key's IIm7 → straight into a two-five-one landing
- **38** Am→C♯m: identical minor two-five-one progression shifted directly (major 3rd up)
- **44** C→E: first half hides a Key=F two-five-one; second half is an altered, modified two-five-one
- **47** four-key two-five chain; a minor two-five resolving to the **parallel major's I** for surprise
- **49** triple two-five reharmonization chain (on-chord-ification + ura-code-ification)

### 3.4 dim / aug Family (V7 stand-ins)

- **40** C→Fm: **Edim ≈ C7(♭9) minus the root** = stand-in for the target key's V7, loudly announcing the turn to minor
- **41** Am→Bm: A♯dim ≈ F♯7(♭9) minus the root; `Am→A♯dim→Bm` = **passing diminished** (パッシング・ディミニッシュ — a dim connecting two chords a whole step apart)
- **42** C→F: **Caug ≈ C7(♭13)** as cushion, containing the ascending chromatic cliché line G→G♯→A
- **43** C→Dm: Aaug ≈ A7(♭13) = stand-in for Dm's V7; the quirky sonority raises the announcement level
- Common thread: each can be swapped back to a plain V7 and still work, but the dim/aug sonorities hit harder and announce more loudly.

### 3.5 Parallel-Shift Family

**Shift an identical progression wholesale** (degrees completely unchanged, strongest unity):
- **01** (minor 3rd up / minor), **02** (minor 3rd down / Canon), **04** (half step down), **09** (whole step down), **15** (half step up), **21** (subdominant key), **32** (Autumn Leaves loop, major 3rd down), **38** (major 3rd up), **41** (whole step up)

**Single-chord half-step shift to a cushion/landing point** (mantra: make a half-step parallel move onto the cushion chord):
- **28**: ♭III (C) → half step up to the new key's V (C♯)
- **29/30**: V → half step down/up to the new key's V
- **32**: after Im resolves, half step up to the new key's **IVm** (the landing point is not limited to V!)
- **33**: Vm7 half step down to the new key's **IIm7**, then two-five-one
- **39**: Im replaced by I, a half-step neighbor of the new key's I

**Whole-step shift** (exceptionally beautiful sonority): **26** (F(onG)→G(onA)), **35** (Em7 → new key's Im7)

**Cushion-free direct jump** (maximum impact): **34** (G7 → G♯m a half step above, taken directly as the new Im), **38** (minor Im is a flexible resolution point, dive straight into the new key)

**I△7 chained parallel motion**: **50** (crossing 6 keys, all-purpose bright template)

### 3.6 On-Chord Family (slash chords, IV(onV))

Principle: IV(onV) ≈ V7(9,11) minus the 3rd and 5th — **no leading tone → dominant function softened, tonal sense ambiguous → "free to fly to any key."**
- **26** C→D: F(onG) shifted up a whole step to G(onA) (= an A7(9,11) revoicing)
- **27** C→E♭m: F6(onG) (≈ G7sus4) sliding to the half-step-neighbor IVm7 of the new key
- **31** Am→B: F6(onG) serving as the "five" of a two-five, then a half-step move to the new key's V
- **43** C→Dm: F6(onG) forming a two-five with Dm7
- **46** C→Em→G: Am7(onD) = a softened revoicing of D7 closing V–I
- **48** Am→Gm→Bm: every seam uses D(onE) and F(onG) — smooth and seamless
- **49** in the chain, F△7(onG), E♭(onF), D♭(onE♭) are all V7s turned into on-chords

### 3.7 Chained-Modulation Family (the unifying recipe)

Universal recipe: **design every "landing chord" with a double identity** (the old key's resolution point = the new key's IIm7/IVm/substitute chord), then drive toward the next key with a two-five (or a reharmonized form of it).
- **22** Am→A♭→E♭: entry via the secondary dominant's ura-code + strong progression + a closing two-five-one that modulates once more
- **44** C→(F)→E: the dominant 7th C7 makes F△7 instantly heard as Key=F's tonic — the "hidden key"
- **45** C→A→F♯m: common-tone cushion (B♭△7 shares 3 notes with Dm7) + ura-code G7
- **46** C→Em→G: substitute-chord entry (Em = C's tonic substitute) + C△7's double identity
- **47** C→Em→E→G→Em: one two-five per bar chained; a minor two-five resolving to the parallel major's I
- **48** Am→Gm→Bm: every seam turned into an on-chord, blurring tonality for a smooth crossing
- **49** C→Cm→B♭m→A♭→F: triple chain of "IIm7 → V7 as on-chord → V7's ura-code → new Im7 (doubling as the next key's IIm7)"
- **50** C→D→E→G→A→B: I△7 parallel motion, voice relationships fully preserved

---

## 4. Appendix: Theory Quick Reference

### 4.1 Chord Function (T / SD / D)

- **Tonic (トニック, T)** = I: the tonal center, most stable; **Subdominant (サブドミナント, SD)** = IV: semi-stable, can move to T or D; **Dominant (ドミナント, D)** = V/V7: V7 contains the **tritone** between its 3rd and 7th, strongly pulling toward resolution to T.
- Major: I△7=T | IIm7=SD | IIIm7=T | IV△7=SD | V7=D | VIm7=T | VIIm7(♭5)=D
- Natural minor: Im7=T | IIm7(♭5)=SD | ♭III△7=T | IVm7=SD | Vm7=D | ♭VI△7=SD/T | ♭VII7=SD

### 4.2 Diatonic Chord Templates (ダイアトニック・コード)

- Major: `I△7, IIm7, IIIm7, IV△7, V7, VIm7, VIIm7(♭5)`
  - e.g. Key=C: C△7, Dm7, Em7, F△7, G7, Am7, Bm7(♭5)
- Natural minor: `Im7, IIm7(♭5), ♭III△7, IVm7, Vm7, ♭VI△7, ♭VII7` (the book thinks in natural minor by default; in practice the harmonic-minor V7 is often borrowed for its leading-tone resolution)
  - e.g. Key=Am: Am7, Bm7(♭5), C△7, Dm7, Em7, F△7, G7
- Harmonic minor: `Im△7, IIm7(♭5), ♭III△7(♯5), IVm7, V7, ♭VI△7, VIIdim`
- Melodic minor: `Im△7, IIm7, ♭III△7(♯5), IV7, V7, VIm7(♭5), VIIm7(♭5)` (source of the VIm7(♭5) in Techniques 25/38/46)

### 4.3 Substitute Chords (代理コード)

| Function | Major primary | Major substitutes | Minor primary | Minor substitutes |
|---|---|---|---|---|
| T | I | IIIm, VIm | Im | ♭III |
| SD | IV | IIm | IVm | IIm(♭5), ♭VI, ♭VII |
| D | V | VIIm(♭5), ♭II7 (ura) | Vm | — |

The theoretical basis for Technique 46's "use Em in place of C to accomplish the C→Em modulation."

### 4.4 Six Standard Devices

1. **Dominant motion** (ドミナント・モーション): V7→I. The sense of resolution comes from two chromatic lines (G7→C: 7th F→E descending, 3rd B→C ascending). Indispensable whenever you want the modulation to "flow naturally."
2. **Two-five(-one)** (ツー・ファイブ（・ワン）): IIm7–V7(–I), the most common cadential module; minor form is IIm7(♭5)–V7–Im. Modulation application = "land via the new key's borrowed two-five-one."
3. **Secondary dominant** (セカンダリー・ドミナント): turn any diatonic chord other than V7 into a dominant 7th, resolving to the diatonic chord a perfect 4th above it.
   - All patterns in Key=C: C7→F / D7→G / E7→Am / A7→Dm / B7→Em
4. **On-chord** (オン・コード, slash chord): bass note inside the chord = an ordinary inversion; bass note outside the chord (e.g. C(onD)) = viewed from the bass it spells "Root·7th·9th·11th" — **no 3rd, function blurred** — and can substitute for a dominant 7th or minor 7th, the key to slippery-smooth modulation.
5. **Ura-code** (裏コード, tritone substitution, ♭II7): shares the same tritone as V7 (G7's B/F = D♭7's F/C♭), so resolution function is equivalent; being non-diatonic it sounds fresher and more stylish, with the bass resolving down a half step (♭II→I). On the circle of fifths it sits directly opposite V (on the diagonal).
6. **Subdominant minor** (サブドミナント・マイナー, IVm): a chord borrowed from the parallel minor, adding a touch of sorrow to a major key (a faintly overcast color).

### 4.5 Interval Quick Reference

- Perfect intervals: perfect unison = 0 semitones | perfect 4th = 5 | perfe

…(truncated)