# Jp Chord Selection

> Method for harmonizing a melody with chords - key identification, diatonic chords, cadences, non-chord tone handling, the three staple progressions, and 7th upgrades. Use when the user has a melody that needs chords, is unsure which chord fits a given measure, or needs to determine the key of a melody.

- Skill: `jtydhr88/jp-chord-selection` (Agent Skill)
- Install (CLI): `npx skillmds@latest add jtydhr88/jp-chord-selection`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jtydhr88/jp-chord-selection/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-chord-selection

---


# Harmonizing a Melody with Chords (メロディへのコードづけ)

Methodology source: Sho Ueda, *Shoho kara Mi ni Tsuku! Chord no Erabikata Manual* ("Learn from the Basics! A Manual for Choosing Chords", Rittor Music), Introduction through Chapter 2.
Core idea: harmonizing a melody is like a jigsaw puzzle (パズル) — a melody never has only one valid harmonization, but "knowledge" is the driving force that gets you closer to the right answer.

## Workflow Overview

Given a melody, work through the following steps in order:

1. **Identify the key** — the biggest shortcut to harmonization
2. **List the diatonic chords (ダイアトニックコード)** — this immediately narrows the candidate pool
3. **Arrange them by cadence (ケーデンス)** — match melody notes measure by measure, fitting them into the T→S→D→T framework
4. **Handle non-chord tones (非和声音)** — decide which melody notes are "decoration" and confirm each one resolves
5. **Substitute / apply staple progressions** — replace I with IIIm, IIm with IV, or drop in one of the three staple progressions directly
6. **Upgrade to 7ths** — function unchanged, sound more stylish (オシャレ)

Simplifying assumption (beginner default): one chord per measure; once fluent, two per measure is fine.

---

## Step 1: Identify the Key

### 1-1 Reasoning from Accidentals

Memorize the two orders in which accidentals are added (key-signature rules):

- **Order of ♯s**: ファ→ド→ソ→レ→ラ→ミ→シ (F → C → G → D → A → E → B)
- **Order of ♭s**: シ→ミ→ラ→レ→ソ→ド→ファ (B → E → A → D → G → C → F — exactly the ♯ order reversed)

Reasoning procedure:

1. Tally the ♯/♭ notes in the melody and compare against the orders above. Example: only F♯ and C♯ appear, G carries no ♯ → most likely a key with 2 sharps.
2. Each key signature maps to **a pair of relative keys (平行調, relative major/minor)** as candidates. 2♯ → D Major or B Minor.
3. **The key to telling major from minor: the minor scale's 7th degree — the leading tone (導音) — is frequently raised a semitone by accidental** (a consequence of the harmonic minor scale).
   - B Minor's leading tone is A♯: if A is never raised in the melody → conclude D Major.
   - If the melody frequently shows "an accidental sharp outside the key signature that happens to be some minor key's leading tone" → interpret it as that minor key.

### 1-2 Distinguishing "Scale Tones" from "Ornamental Notes"

Accidentals (変化記号) in a melody come in two identities:

- **音階固有音** (notes inherent to the key's scale): the sharps/flats the scale itself carries
- **装飾音** (ornamental notes): temporary decoration, unrelated to the key

Note-by-note elimination rules:

| Observation | Judgment |
|---|---|
| The same note appears both with and without a ♯ | The ♯ version is very likely just decoration; the true note is ♮ |
| A note carries a ♯, but notes that should carry ♯ earlier in the ♯ order do not | That ♯ is unlikely to be a scale tone (e.g., ラ♯ appears but no ソ♯/レ♯ → ラ♯ is decoration) |
| A ♭ note sits right next to the same note as ♮, apparently setting up a descent | Ornamental note |
| Accidentals remaining after elimination | Assume they are scale tones, match them against the key-signature table to name the key, then use the leading-tone test to pick major vs minor |

Worked note-by-note example (♯s appear on ラ, ド, ファ; ♭ appears only on ミ):

1. **ド**: both C♯ and C♮ occur → C♯ is very likely just decoration → the true note is C♮;
2. **ラ♯**: if it were a scale tone, then by the ♯ order G and D would also have to be sharped, and they are not → ornamental; the true note is A♮;
3. **ミ♭**: an E♮ sits adjacent, and it appears to set up a descent to D → ornamental;
4. **ファ♯**: cannot be eliminated directly → assume it is a scale tone: "a key where C is ♮ and F carries a ♯" = G Major or E Minor;
5. **Leading-tone test**: E Minor's leading tone is D♯, which should appear frequently; the score has none → conclude **G Major**.

### 1-3 Key Identification Is Inherently Ambiguous

The same melody may admit two legitimate readings (e.g., C Major with C→G→C, or A Minor with Am→E7→Am). In that case, decide from **context and the mood (ムード) of the whole piece**. Beyond theoretical deduction, the intuition of "feeling" the key from the melody matters most — play it and sing it before reasoning.

### Key Signature Quick Reference

| 调号 | 大调 | 小调（平行短調） | | 调号 | 大调 | 小调 |
|---|---|---|---|---|---|---|
| 无 | C | Am | | 1♭ | F | Dm |
| 1♯ | G | Em | | 2♭ | B♭ | Gm |
| 2♯ | D | Bm | | 3♭ | E♭ | Cm |
| 3♯ | A | F♯m | | 4♭ | A♭ | Fm |
| 4♯ | E | C♯m | | 5♭ | D♭ | B♭m |
| 5♯ | B | G♯m | | 6♭ | G♭ | E♭m |
| 6♯ | F♯ | D♯m | | 7♭ | C♭ | A♭m |

---

## Step 2: List the Diatonic Chords (ダイアトニックコード)

Chain of logic: **key determined → diatonic chords can be listed → candidate chords are fixed**. Diatonic chords = chords built by stacking thirds on each scale degree, using only notes within that key's scale.

### Major-Key Diatonic Chords (C Major as example)

| 级数 | I | IIm | IIIm | IV | V | VIm | VIIm(♭5) |
|---|---|---|---|---|---|---|---|
| C 大调 | C | Dm | Em | F | G | Am | Bm(♭5) |
| 功能 | T | S | ※变色龙 | S | D | T | D |

Transpose by degree to any major key, e.g. F Major: F(I)–Gm(IIm)–Am(IIIm)–B♭(IV)–C(V)–Dm(VIm)–Em(♭5)(VIIm(♭5)).

**In practice, master these 5 first: I, IIm, IV, V, VIm.**
- IIIm is a "chameleon chord that changes its role by context" — skip it at the beginner stage;
- VIIm(♭5) is rarely used as D; for the dominant function, prefer V.

### Chord Construction Rules (in Semitones)

Interval quick reference (semitones between two notes):

| 音程 | 半音数 | 音程 | 半音数 |
|---|---|---|---|
| 短2度 | 1 | 完全5度 | 7 |
| 長2度（全音） | 2 | 短6度 | 8 |
| 短3度 | 3 | 長6度 | 9 |
| 長3度 | 4 | 短7度 | 10 |
| 完全4度 | 5 | 長7度 | 11 |
| 増4度/減5度 | 6 | 完全8度 | 12 |

The four triads (トライアドコード, triad chords; semitones stacked upward from the Root):

| 和弦 | 结构（下+上三度） | 半音数 | Root–5音 | 例（C 系） |
|---|---|---|---|---|
| Major | 長3 + 短3 | 4+3 | 完全5度 | C = C E G |
| Minor（m） | 短3 + 長3 | 3+4 | 完全5度 | Cm = C E♭ G |
| m(♭5)／dim | 短3 + 短3 | 3+3 | 減5度 | Cm(♭5) = C E♭ G♭ |
| aug | 長3 + 長3 | 4+4 | 増5度 | Caug = C E G♯ |

Principal 7th chords (triad + 7th; parentheses give semitones from Root to the 7th):

| 和弦 | 结构 | 半音数 | 例 | Notes |
|---|---|---|---|---|
| △7（Major 7th） | major triad + 長7度 | 4+3+4（11） | C△7 = C E G B | Also written CM7; a distinctly stylish sound |
| 7（dominant 7th, ドミナントセブンス） | major triad + 短7度 | 4+3+3（10） | C7 = C E G B♭ | Most frequently used; the 3rd–7th form a 減5度 (tritone), the source of its tension |
| m7 | minor triad + 短7度 | 3+4+3（10） | Cm7 = C E♭ G B♭ | More delicate than a plain minor triad |
| m7(♭5) | dim triad + 短7度 | 3+3+4（10） | Cm7(♭5) = C E♭ G♭ B♭ | Also called half-diminished (ハーフディミニッシュ, ∅); common in minor keys |
| dim7 | dim triad + 減7度 | 3+3+3（9） | Cdim7 = C E♭ G♭ B♭♭ | Contains two 減5度 intervals; extremely distinctive character |
| 6 | major triad + 長6度 | 4+3+2（9） | C6 = C E G A | Commonly used; m6 works the same way |

Fast method for building any chord (E♭ as example): first fix the outer frame — a **perfect 5th above the Root** (E♭→B♭, 7 semitones, never wrong) — then fill the inside: 4-below/3-above for Major, 3-below/4-above for Minor.

Supplementary general rules:
- If the constituent notes match, the symbol stays the same regardless of how open the voicing is or whether notes are doubled.
- **転回形 (inversion)**: when the Root is not the lowest note, write C(onG) or C/G (read "C on G"); inversion does not change the Root.
- A chord symbol is only a rough representative of "the harmony governing this passage" — notes outside the symbol sounding on the page is perfectly normal (those are non-chord tones; see Step 4).

### Degree Name (ディグリーネーム) Notation Rules

This skill uses dual notation throughout — "letter + degree" — with degree rules as follows:

1. The Roman numeral indicates "which scale degree of the current key the chord's Root sits on"; the quality suffix carries over as-is: Dm→IIm, G7→V7, C△7→I△7;
2. Non-diatonic chords are labeled by the Root's alteration relative to the scale tone: C♯dim7 in C Major → ♯Idim7;
3. **Change the key and the degree changes**: the chord C is I in C Major but IV in G Major;
4. Minor-key degrees are referenced to the relative major: A♭ in C Minor → ♭VI.

---

## Step 3: Arrange by Cadence (ケーデンス)

The "grammar" of chord ordering is called **ケーデンス (cadence; the German-derived term is カデンツ)**.

### The Three Functions

| Function | Japanese | Character | Members |
|---|---|---|---|
| T（Tonic） | トニック (tonic function) | Stable | I, VIm (VIm is I's "body double / stand-in") |
| S（Sub Dominant） | サブドミナント (subdominant function) | Mildly unstable, propels toward D | IIm, IV |
| D（Dominant） | ドミナント (dominant function) | Unstable, wants to return to T | V, VIIm(♭5) (V is overwhelmingly more common) |

D's instability must "resolve" onto T; this psychological need is precisely the source of **musical forward momentum**. IIIm is excluded from this list (chameleon).

### The Three Cadence Types

1. **T → D → T**: like "stand up, bow, sit down" — simple and forceful. Examples: C→G→C (I→V→I), Am→G→C (VIm→V→I)
2. **T → S → D → T**: tension rises gradually, then resolves onto T in one stroke — the most "satisfying". Examples: C→F→G→C (I→IV→V→I), Am→Dm→G→C (VIm→IIm→V→I)
3. **T → S → T**: returns to T without passing through D; S→T is usually IV→I, commonly called the **アーメン終止 (Amen cadence / plagal cadence)**. Example: C→F→C (I→IV→I)

**同機能の連用 (consecutive use of same-function chords)**: chords of the same function may be chained. Example: C→Am→F→Dm→G→C (I→VIm→IV→IIm→V→I) — I+VIm chained as T, IV+IIm chained as S; the whole is still T→S→D→T.

### Measure-by-Measure Harmonization Procedure

1. **Confirm the essentials**: write out the key's I, IIm, IV, V, VIm with their functions, plus the three cadence types.
2. **List candidates per measure**: take that measure's melody notes and find the diatonic chords whose constituent notes contain them.
   - Melody notes exactly match a chord's tones → direct candidate (e.g., measure notes A·F·C → F);
   - Multiple chords contain the notes → parallel candidates (e.g., B♭·D → B♭ or Gm, both S).
3. **Adjudicate by cadence**: if the first three measures already form T→S→D, measure four should return to T — pick the T-function candidate (F or Dm both work; choose by taste).
4. **Ending rule**: closing the piece on the most stable chord, **I**, is best.
5. **T is both endpoint and starting point**: in a function chain like T S D T S T D T, one T is often shared by the cadence before and the cadence after it.

### Worked Example: F Major, 3/4 Time, 8 Measures

First write out the candidate table: F(I,T), Gm(IIm,S), B♭(IV,S), C(V,D), Dm(VIm,T). Then measure by measure:

| 小节 | 旋律音 | Candidates containing those notes | Cadence ruling |
|---|---|---|---|
| 1 | A・F・C | F (constituent notes match exactly) | F（T） |
| 2 | B♭・D | B♭ or Gm (both S) | Either works |
| 3 | E・G・C | C | C（D） |
| 4 | A | F or Dm (both T) | The first three measures form T→S→D, so return to T here; either works |
| 5–8 | (same method) | B♭ → F → C → F | S→T→D→T, closing on I |

Result: **F → B♭(or Gm) → C → F(or Dm) ／ B♭ → F → C → F**; overall function chain T S D T S T D T.

Second major-key example (C Major, 8 measures, melody containing non-chord tones):
**C → F → Dm → G ／ C → Am → Dm → G → C**
Degrees I → IV → IIm → V ／ I → VIm → IIm → V → I; functions T → S (IV and IIm chained) → D ／ T (I and VIm chained) → S → D → T — the cadence completes twice. Rule of thumb: **trying to fit the cadence framework as much as possible first is the shortcut to improvement**.

Caveat: real songs are full of examples that do not obey the theory. Insisting "the cadence must hold absolutely" can itself produce unnatural progressions — stay flexible and remember that "everything has exceptions."

---

## Step 4: Handling Non-Chord Tones (非和声音)

### Concepts

- **和声音 (Chord Tone)**: a melody note that belongs to the current chord's constituent notes.
- **非和声音 (Non-Chord Tone)**: a melody note that does not belong to the current chord's constituent notes (e.g., a D over a C chord).

All chord tones → correct but overly plain; saturated with non-chord tones → jarring (チグハグ). Balancing the ratio is a matter of experience and taste. Non-chord tones are "accessories," not "obstacles" — their urge to return to a chord tone generates forward momentum, a "slightly naughty charm (ちょいワルな色気)."

### Three Behavioral Traits

1. **They "resolve" (非和声音の解決)**: a non-chord tone is essentially an altered form of a chord tone; most resolve to the **nearest chord tone**, and they may also resolve toward a constituent note of the **next chord**.
2. **They cannot be left hanging**: a non-chord tone that jumps into the next chord unresolved sounds wrong. Fix: **insert a better-fitting chord that turns the note into a chord tone** (e.g., an awkward A between C→G — insert F, giving C→F→G).
3. **They come in four types**:

| Type | Japanese (reading) | Definition |
|---|---|---|
| Passing tone | 経過音（けいかおん） | Moves stepwise in order through the space between two chord tones of different pitch |
| Appoggiatura | 倚音（いおん） | A non-chord tone falling on a strong beat, usually resolving by step up or down |
| Suspension | 掛留音（けいりゅうおん） | A chord tone of the previous chord held over as-is (often tied, タイ), becoming a non-chord tone over the new chord before resolving |
| Neighbor tone (auxiliary tone) | 刺繡音（ししゅうおん） | "Stitches" around a chord tone: chord tone → neighbor → back to the original note |

### Practical Implications

- For the same melody, **which note you interpret as the chord tone changes the harmonization** (the same melody can take Dm→G or C→Dm) — adjudicate via cadence and surrounding context.
- Self-check after harmonizing: circle every non-chord tone and confirm each belongs to one of the four types and has a resolution destination.
- Reverse application: when writing accompaniment, deliberately embedding "non-chord tone → resolution" motion yields a forward drive that plain arpeggios cannot provide.

---

## Minor-Key Harmonization (Based on the Harmonic Minor Scale)

The rules are **(almost) identical to major** — arrange diatonic chords by cadence. "Almost," because minor has three scales, and the diatonic chords differ subtly depending on which scale you use.

### The Three Minor Scales

1. **自然的短音階 (natural minor scale)**: whole–half–whole–whole–half–whole–whole; **the minor key's signature is determined by this scale**.
2. **和声的短音階 (harmonic minor scale)**: raises the 7th degree a semitone, creating the **導音 (leading tone)** — entering the tonic from a semitone below; the leading tone is written with an accidental. **Most important for harmonization; must be memorized.**
3. **旋律的短音階 (melodic minor scale)**: ascending, the 6th degree is also raised (eliminating the augmented 2nd, easier to sing); the descending form = natural minor.

### Diatonic Chords of the Harmonic Minor Scale (C Minor as example)

| 级数 | Im | IIm(♭5) | ♭IIIaug | IVm | V | ♭VI | VIIm(♭5) |
|---|---|---|---|---|---|---|---|
| c 小调 | Cm | Dm(♭5) | E♭aug | Fm | G | A♭ | Bm(♭5) |
| 功能 | T | S | ×几乎不用 | S | D | T※ | D |

Diatonic chords of all three scales compared (C Minor, for reference):

| 音阶 | 各级和弦 | 功能 |
|---|---|---|
| 和声小音阶 | Cm・Dm(♭5)・E♭aug・Fm・G・A♭・Bm(♭5) | T・S・×・S・D・T・D |
| 自然小音阶 | Cm・Dm(♭5)・E♭・Fm・Gm・A♭・B♭ | T・S・T・S・D・T・S |
| 旋律小音阶(上行) | Cm・Dm・E♭aug・Fm・G・Am(♭5)・Bm(♭5) | T・S・×・S・D・T・D |

- Minor-key degrees are labeled relative to the relative major (A♭ in C Minor is written ♭VI).
- ♭IIIaug has a peculiar sound and is almost never used in ordinary cadences; the natural minor's ♭III can be viewed as "the relative major's I."
- ♭VI is treated as T in classical theory, but jazz/pop often treats it as S (its notes are close to IVm); this method adopts the easier-to-grasp classical reading, **T**.

**In practice, master these 5 first: Im, IIm(♭5), IVm, V, ♭VI** (in C Minor: Cm, Dm(♭5), Fm, G, A♭; functions T, S, S, D, T).

Basic minor example: A Minor harmonized as T→S→D→T gives **Am → Bm(♭5) → E → Am (Im → IIm(♭5) → V → Im)**.

### Key Technique: Inserting the Relative Major's V→I

Inserting the **relative major's (平行長調)** V→I into a minor progression creates a momentary brightness like "light breaking through a gap in the clouds" — extremely common.

C Minor 8-measure demonstration:
**Cm → Fm → B♭ → E♭ → A♭ → Dm(♭5) → G → Cm**
Degrees: Im(T) → IVm(S) → **[E♭ Major's V(D) → I(T)]** → ♭VI(T) → IIm(♭5)(S) → V(D) → Im(T)

The key to returning to the home key is using a **common chord as the "hinge" (蝶番, ちょうつがい)**: A♭ is IV from E♭ Major's viewpoint and ♭VI from C Minor's, sliding the music smoothly back into the minor key.

### Minor-Key Worked Example (A Minor, 3/4 Time, 8 Measures)

Exactly the same procedure as major: first list Am(Im,T), Bm(♭5)(IIm(♭5),S), Dm(IVm,S), E(V,D), F(♭VI,T), then match melody notes measure by measure and adjudicate by cadence. Sample solution:

**Am → Dm → G → C ／ F → Bm(♭5) → E → Am**
- First half: Im(T) → IVm(S) → **[C Major's V(D) → I(T)]** — the relative major mixed in mid-course;
- Second half: ♭VI(T) → IIm(♭5)(S) → V(D) → Im(T); the common chord **F** (C Major's IV / A Minor's ♭VI) acts as the hinge (蝶番);
- This progression is identical to the classic *Autumn Leaves* (枯葉); harmonizing measure 5 with Dm (IVm, S) is also fine — Dm is likewise a common chord of both keys.

---

## Step 5: The Three Staple Progressions and Substitution

### Substitution Rules (Two, for Beginners)

- Within a progression, **I (T) may be replaced by IIIm** (IIIm is I's substitute);
- **In the S segment, IIm may be replaced by IV** (and vice versa; same function, interchangeable).

### Staple #1: 循環コード (Cyclic Progression)

**I → VIm → IIm → V** (C Major: C → Am → Dm → G), functions T→T→S→D. "Cyclic" means it can repeat indefinitely — the staple of staples (*Stand by Me*, etc.).
Chained variant example: C→Am→Dm→G ／ Em→Am→F→G (I→VIm→IIm→V ／ IIIm→VIm→IV→V).

### Staple #2: 逆循環コード (Reverse Cyclic Progression)

**IIm → V → I → VIm** (C Major: Dm → G → C → Am), functions S→D→T→T — i.e., the cyclic progression started from its S segment. Used mainly in major keys, arguably even more often than the cyclic form (*ヘビーローテーション* (Heavy Rotation), *君の瞳に恋してる* (Can't Take My Eyes Off You), etc.).
Most common development: repeat twice, ending on I the second time; or on the repeat, turn the final VIm into a **VI major triad**:
Dm→G→Em→Am ／ Dm→G→C→**A** (IIm→V→IIIm→VIm ／ IIm→V→I→VI).

### Staple #3: パッヘルベルのカノン型 (Pachelbel's Canon Type)

**I → V → VIm → IIIm → IV → I → IIm → V** (C Major: C → G → Am → Em → F → C → Dm → G).
Especially common in J-POP (*ハナミズキ* (Hanamizuki), *チェリー* (Cherry), etc.). Its charm: from the constituent notes of the chords you can extract a **stepwise descending melodic line** that turns upward at the final chord — an emotional effect of "a sliver of hope suddenly emerging," extremely useful for both songwriting and accompaniment.

Transposition: move it by degree to any key (e.g., F Major: F C Dm Am B♭ F Gm C).

---

## Step 6: Upgrading to 7ths

### Core Conclusion: 7th Chords Have Exactly the Same Function as Their Triads

Major-key diatonic 7th chords (ダイアトニック7thコード, C Major):

| C△7 | Dm7 | Em7 | F△7 | G7 | Am7 | Bm7(♭5) |
|---|---|---|---|---|---|---|
| I△7(T) | IIm7(S) | IIIm7(※) | IV△7(S) | V7(D) | VIm7(T) | VIIm7(♭5)(D) |

So direct substitution is fine: C→F→G→Am (I→IV→V→VIm) ⇒ C△7→F△7→G7→Am7, no problem at all.
**Five to remember is enough: I△7, IIm7, IV△7, V7, VIm7.**

### V7 Is the Protagonist That Pulls the Music Forward

The most frequently used diatonic 7th is **V7 (属七の和音, the dominant 7th chord)**: structurally the union of the triads V and VIIm(♭5) (G + Bm(♭5) = G7). Its Dominant pull is exceptionally strong — use it actively.

### 7ths Widen Your Harmonization Options

**A melody note may be interpreted as the chord's 7th** to justify a 7th chord (e.g., melody note B over C → harmonize with C△7). Many "nothing seems to fit" melodies suddenly open up. Even when the melody contains no 7th, you may use a 7th purely for the stylish sound.

### Minor-Key 7ths (Harmonic Minor Scale, C Minor)

| Cm△7 | Dm7(♭5) | E♭△7(♯5) | Fm7 | G7 | A♭△7 | Bdim7 |
|---|---|---|---|---|---|---|
| Im△7(T) | IIm7(♭5)(S) | ×几乎不用 | IVm7(S) | V7(D) | ♭VI△7(T) | VIIdim7(D) |

The other two scales' 7th versions (for reference, C Minor):
- Natural minor: Cm7(Im7,T)・Dm7(♭5)・E♭△7(♭III△7,T)・Fm7・Gm7(Vm7,D)・A♭△7・B♭7(♭VII7,S)
- Melodic minor (ascending): Cm△7・Dm7(IIm7,S)・E♭△7(♯5)(×)・Fm7・G7・Am7(♭5)・Bdim7

Practical points for minor:
- **Im△7 has a fairly jarring sound; the natural minor's Im7 is usually substituted for it**;
- → Five to remember in minor: **Im7, IIm7(♭5), IVm7, V7, ♭VI△7**;
- The relative major's V→I can likewise be 7th-ized (V7→I△7, or 7th-ize only one of the two).

C Minor 8-measure comprehensive demonstration:
**Cm7 → Fm7 → B♭7 → E♭△7 → A♭△7 → Dm7(♭5) → G7 → Cm7**
(Im7 → IVm7 → [relative major E♭'s V7→I△7] → ♭VI△7 → IIm7(♭5) → V7 → Im7)

Practical example of minor reverse-cycle + 7th-ized relative major (D Minor, 8 measures):
**Dm7 → Gm7 → C7 → F△7 ／ B♭△7 → Em7(♭5) → A7 → Dm**
The first half is [relative major F Major's V7→I△7] (C7→F△7); then the common chord B♭△7 serves as the hinge (蝶番) back to D minor (IIm7(♭5)→V7→Im).

### Dosage Warning

7ths are rich and complex in sound — **you need not use them everywhere**: restricting yourself to V7 alone, or adding only IIm7, gives a calmer sound less likely to clash with the melody. Do not overdo it — "observe the dosage and directions; use correctly."

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## Classic-Song Proof: Less Is More

*草競馬 (Camptown Races)* (S. Foster, F Major) uses only **3 chords in the entire song: F(I), C7(V7), B♭(IV)**:

- Section [A]: F ↔ C7 — a **plain alternation of T and D** — the music just keeps pressing forward;
- Section [B]: **the S-function B♭ makes its first appearance** — a chord never heard before transforms the color, producing a flowing "the view suddenly opens up" sensation;
- Section [C] returns to C7→F to close.

Lesson: just 3 chords plus a simple melody can build a three-dimensional world; **the "late arrival" of the S chord is a classic device for creating sectional color change**. When harmonizing your own melody, you need not chase richness in every measure — first decide "which function makes its entrance in which section."

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## Quick FAQ

**Q: The melody notes in a measure don't fully belong to any common chord?**
Treat the misfit notes as non-chord tones (confirm they belong to one of the four types and have a resolution destination) and choose the chord from the remaining notes; or interpret the note as a 7th and use a 7th chord; failing that, consider two chords in the measure, assigning the note to the second chord that fits it.

**Q: Two candidate chords both make sense — which to pick?**
Function first — pick the chord whose function the cadence demands; among same-function parallel candidates (e.g., B♭ vs Gm, F vs Dm), choose by personal taste and color. There is no single correct answer.

**Q: The melody sounds sad — can I conclude it's minor?**
No. Reason from accidentals plus the leading-tone test (Step 1); if genuinely ambiguous, decide by context and the piece's overall mood, and verify by actually playing and singing.

**Q: Must each measure have exactly one chord?**
Beginner default is one per measure; when melody notes are dense or the function needs to switch, two chords per measure (usually split on the strong beat) is very common.

**Q: Want a flash of brightness in a minor progression?**
Insert the relative major's V→I (or V7→I△7), then slide back to the home key via a common chord (the hinge, 蝶番).

**Q: The result sounds too bland?**
Try in order: same-function substitution (IIIm for I, IV for IIm) → apply a staple progression → localized 7th-izing (V7 first) → have an S-function chord make a "late arrival" in a new section for a color change.

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## Quick Checklist

Self-check after harmonizing a melody:

- [ ] Key identification is grounded (accidental order + leading-tone test), and the relative key's alternative reading was considered
- [ ] All chords used are within the key's common 5 (major: I/IIm/IV/V/VIm; minor: Im/IIm(♭5)/IVm/V/♭VI), with justified exceptions
- [ ] The function chain reduces to the three cadence types (including same-function chaining), ending on I (or a deliberately open ending)
- [ ] Every melody note in each measure is either a chord tone or one of the four non-chord tone types with a resolution
- [ ] Minor keys harmonized from the harmonic minor scale; for momentary brightness, consider the relative major's V→I plus a common-chord "hinge" (蝶番) return
- [ ] 7ths used only where needed, V7 first

## Terminology Quick Reference (Japanese → English)

| Japanese | English | Japanese | English |
|---|---|---|---|
| コードづけ | Harmonizing a melody | ダイアトニックコード | Diatonic chords |
| ケーデンス／カデンツ | Cadence | トニック（T） | Tonic function |
| ドミナント（D） | Dominant function | サブドミナント（S） | Subdominant function |
| 導音 | Leading tone | 平行調 | Relative major/minor keys |
| 和声的短音階 | Harmonic minor scale | アーメン終止 | Amen (plagal) cadence（IV→I） |
| 和声音／非和声音 | Chord tone / Non-chord tone | 経過音 | Passing tone |
| 倚音 | Appoggiatura | 掛留音 | Suspension |
| 刺繡音 | Neighbor tone (auxiliary tone) | 蝶番 | Hinge (common-chord pivot) |
| 循環コード | Cyclic progression | 逆循環コード | Reverse cyclic progression |
| パッヘルベルのカノン型 | Pachelbel's Canon type | 属七の和音 | Dominant 7th chord（V7） |
| 転回形 | Inversion | 定番コード進行 | Staple chord progression |