jp-composition-basics

name	jp-composition-basics
description	J-Pop composition fundamentals - the full composition workflow (drums → chords → bass → melody), basic music theory, rhythm patterns, diatonic chords, and cadences. Use when the user wants to write a J-Pop/Japanese-style song from scratch, asks about the step-by-step composition workflow, or needs basic music theory (intervals/chord construction/scale degrees/functional harmony).

J-Pop Composition Basics

Purpose: write a J-Pop song from zero; look up composition workflow steps; look up basic theory (intervals/degrees/chord construction/functional harmony/cadences/rhythm patterns).

Sources: 《できる ゼロからはじめる作曲 超入門》 (Hidetoshi Takumi) + 《もっと！思いどおりに作曲ができる本》 (Ken Kawamura), Chapter 1. Intended as a working reference while actually writing songs. All examples default to Key=C, 4/4 time; to change key, shift by Roman-numeral degrees (12-key diatonic chord tables in reference.md). Chord progressions are always notated both ways: letter symbols plus Roman-numeral degrees.

1. The Full Composition Workflow (Recommended Order)

Trade-offs between the two starting points:

• Melody-first (メロディ先行): melodies come out naturally singable, and harmony can be tailored to the melodic climax; but beginners struggle to pick chords for a melody, and the connections easily turn awkward.
• Harmony-first (ハーモニー先行): using stock chord patterns (コードパターン) locks in the mood quickly and the connections flow smoothly; but melodic motion gets constrained and easily turns bland.
• Recommended for beginners: lay down a chord progression from stock patterns first, then place the melody on top; the ideal state is conceiving both in parallel.

Mindset: in pop/rock/jazz, thinking about music in terms of chords is itself "small-scale composing" (小さな作曲) — deciding chord order and how to play them, making phrases and rhythm patterns, thinking about arrangement: all of it counts as composition. Not reading notation or playing an instrument is no barrier to starting.

This skill's complete production workflow (minimal "one-person band" instrumentation):

① Drums (ドラム)       Build an 8-bar 8-beat drum pattern (velocity dynamics, fills in bars 4/8, Crash at section start)
② Chords (コード)      Assemble 8 bars from cadences/stock patterns → substitute chords → harmonic rhythm → voice leading
③ Bass (ベース)        Root notes on strong beats, rhythm locked to the Kick, adjust Duration, add octaves/fifths/ornament tones
④ Backing (バッキング)  Add minimal rhythm to the chords (comping/コンピング), balance three track volumes to leave room for the melody
⑤ Melody (メロディ)    Pick timbre & range → pentatonic scale → draw the outline → vertical ornaments → horizontal adjustments → motif repetition/contrast → 8 bars
⑥ Sections (セクション) 8-bar sections ×2–3 form 1 chorus-cycle (A-melo → B-melo → sabi), with three-element contrast between sections

• The three great elements of music: melody (メロディ, the song's face), rhythm (リズム, speed and groove), harmony (ハーモニー, the "clothing" that determines the overall impression). The bass straddles harmony and rhythm — the hub connecting the two (the unsung hero).
• Register layering convention (piano roll): low octave = bass (around C1–C2), middle octave = chords, high octave = melody. C3 = middle C (some software labels it C4).
• Free DAWs to start with: Studio One Prime (Win/Mac), Cakewalk by BandLab (Win), GarageBand (Mac/iOS).

2. Rhythm and Drums

Beat, Meter, and Metric Accent

• Tempo = the speed of the beat (BPM = beats per minute; BPM 60 → 1 beat = 1 second, BPM 120 → 1 beat = 0.5 seconds).
• Beat feel (8ビート/16ビート) = how densely each beat is subdivided (halved → 8-beat, quartered → 16-beat). The two are independent: the same absolute Hi-hat interval is an 8-beat at BPM 120 but sounds like a 16-beat at BPM 60.
• Weight structure of 4/4 (two stacked duple meters): beat 1 strongest, beat 2 weak, beat 3 medium-strong, beat 4 weakest (◎ ○ large○ small○).
• 表拍/裏拍 = downbeat/offbeat (on-beat/back half of the beat). Shifting an accent off its expected beat position = syncopation (シンコペーション); an accent shifted earlier is strictly called anticipation (アンティシペーション). It is a defining trait of pop music — use it actively.
• Applying strong/weak beats: rhythm patterns, chord-change timing, and melodic accents are all placed with reference to the strong beats (the bass must put the root on the strong beat where the chord changes — see Section 6), which is what makes the finished track feel tight.

The Drum Kit and Basic Patterns

The three essential kit pieces = Kick (キック, bass drum, "don"), Snare (スネア, "ta"), Hi-hat (ハイハット, "chi") — the basic beat is built from these three alone. Crash (クラッシュ) marks the accent at the start of a section; Toms (タム) are used in fills before section changes / in the second half of a bar.

Pattern	Hi-hat	Snare	Kick
8-beat (8ビート) (first choice)	Steady 8th notes (8 hits per bar, closed)	Beats 2 & 4 = backbeat (バックビート)	Beat 1 + other 8th-note slots avoiding the snare (e.g. the offbeat of beat 2)
16-beat (16ビート)	Steady 8ths or 16ths	Beats 2 & 4	Free placement on the 8th/16th grid; 16th offbeats give a busier feel
Shuffle (シャッフル)	Triplet positions 1 & 3 (12 slots per bar)	Beats 2 & 4	Same as Hi-hat (triplet positions 1 & 3)

• 16-beat shuffle: 24 slots per bar; take positions 1, 3, 4, 6 of each sextuplet.
• GM drum mapping: Kick=C1, Snare=D1, Closed HH=F#1, Open HH=A#1, Toms=F1/G1/A1/B1. Non-GM sound sources may map differently.
• For a first composition, go straight to the 8-beat — the foundation of rock/pop — and make variations by adding/removing Kicks on the 8th-note slots.

Velocity and Groove (グルーヴ)

Adding dynamics to a mechanical beat = the core of groove. Velocity design for each 8-beat kit piece:

1. Hi-hat: within each beat, alternate the two 8ths as "strong–weak";
2. Snare: beats 2 & 4 are metrically weak positions, but hitting them deliberately hard manufactures forward drive (the backbeat);
3. Kick: beat 1 strong, offbeat of beat 3 weak; a Kick landing on the offbeat of beat 2, if it is an anticipation of "the strong beat 3 pulled one 8th earlier", is treated as strong.

• The three ingredients of groove: velocity dynamics + tiny timing offsets (human "feel" off the grid) + note lengths and gaps (rests).
• Another source of heaviness/lightness (relative timing): a Snare slightly behind the Kick = heavy; slightly ahead = light.
• Velocity literally means "key-strike speed": the faster, the sharper the attack and the louder the note.

Extending the Drum Track: 1 → 2 → 4 → 8 Bars

Pop melodies use 8 bars as one integral unit. Extension rules:

1. 1 → 2 bars: copy, then make a small local change in bar 2 (e.g. change the Hi-hat on the offbeat of beat 4 from closed to open).
2. 2 → 4 bars: bar 4 = the "comma" (読点 「、」) of the 8-bar whole; put a light fill = fill-in (フィルイン, also called okazu おかず, lit. "side dish") at its end (e.g. one Snare each on the down- and off-beat of beat 4: "tan-tan").
3. 4 → 8 bars: bar 8 is the biggest dividing point of the whole section; the fill must be longer than bar 4's, more finely subdivided, and include Toms. Example (16th grid): beat 3 downbeat Floor Tom "don" + offbeat 16th Snare ×2 "taka"; beat 4 downbeat 16th Snare ×2 "taka" + offbeat high Tom "ton".
4. Section-start marker: replace the Hi-hat on beat 1 of bar 1 with a Crash ("shaan").

Writing conventions: during a fill, continuously-ticking parts like the Hi-hat stop; the Crash is normally struck together with a Kick or Snare. Style notes: hip-hop/electronic music uses 32nd-note Hi-hat runs and 16th-note triplets to create a "stumbling" feel; the drum-machine aesthetic (ドラムマシン, iconic example: Roland TR-808) deliberately gives no dynamics to Hi-hat/Snare — cold, flat, and proud of it.

3. Basic Theory Quick Reference

Note Values and Notation Basics

• There are only 12 basic pitches (7 naturals + ♯/♭), cycling every octave — you can make music without reading notation, but staff notation is the most efficient communication tool when collaborating.
• Note-value fruit mnemonic (each level halves): whole note = suika (スイカ, watermelon) → half = melon (メロン) → quarter = ringo (リンゴ, apple) → 8th = mikan (ミカン, mandarin orange) → 16th = ichigo (イチゴ, strawberry).
• Time signatures: 4/4 (written "C") = one bar holds 4 "apples"; 3/4 = 3 apples; 12/8 = 12 mandarins. Every bar must be completely filled with notes or rests (詰め物, "stuffing").
• Dotted note (付点) = duration ×1.5; triplet (3連符) = one beat divided in 3. Distributing the various notes/rests across a bar = fu-wari (符割り, rhythm partitioning).
• When a complex rhythm is hard to read: convert everything to 8th or 16th notes and count — instantly clear.
• Accidentals: ♯ raises a semitone, ♭ lowers one, ♮ cancels; F♯ = G♭ (enharmonic equivalents). A key signature is written at the head of the staff and applies to every same-named note in the whole piece (all octaves); an accidental applies only within its bar and does not affect same-named notes in other octaves. 8va = play an octave higher, 8vb = an octave lower.

Note Names and Intervals (Degrees)

• Do=C, Re=D, Mi=E, Fa=F, Sol=G, La=A, Si=B (careful: Do is C, not A — a very common beginner error). Japanese note names = ハニホヘトイロ (Ha-Ni-Ho-He-To-I-Ro).
• Degree-counting mnemonic (starting from the root, move one semitone per syllable chanted, black keys included):

Mnemonic	Semitone steps	Result
りんご (ringo, "apple")	3	Major 2nd (−1 semitone = minor 2nd)
さくらんぼ (sakuranbo, "cherry")	5	Major 3rd (−1 semitone = minor 3rd)
パイナップル (painappuru, "pineapple")	6	Perfect 4th (+1 semitone = augmented 4th)
グレープフルーツ (gurēpufurūtsu, "grapefruit")	8	Perfect 5th (−1 = diminished 5th, +1 = augmented 5th)
こたつのうえのミカン (kotatsu no ue no mikan, "a mandarin on the kotatsu")	10	Major 6th (−1 semitone = minor 6th)

• 2nd, 3rd, 6th, 7th use major/minor (長/短); 1st, 4th, 5th, 8th use perfect/augmented/diminished (完全/増/減). The root itself = perfect unison (完全1度, ユニゾン); the octave = perfect 8th.
• 7th shortcut: count downward from the octave root — a semitone below = major 7th (△7), a whole tone below = minor 7th (7th). Works in every key.
• Tension-degree "subtract 7" rule: 9th−7 = 2nd, 11th−7 = 4th, 13th−7 = 6th (♭9=♭2, ♯9=♯2, ♯11=♯4, ♭13=♭6). ♭11 (= the 3rd) and ♯13 (= same pitch as the 7th) do not exist.
• Degree-name (ディグリーネーム) writing rule: in chord names, ♯/♭ goes after the letter (D♯m7); in degree names, it goes before the Roman numeral (♯IIm7). Degrees stay the same after transposition — the same progression in different keys is recognizable at a glance.

Chord Construction

How triads are built (two-step method): take a scale note as 1, pair it with the 5th note above (the fifth), then insert the 3rd note in the middle (the third) → "1·3·5, every other note" is the basis of all chords. The 7 diatonic triads fall into 3 types by their stack of thirds:

• Major chord (メジャーコード) = major 3rd below + minor 3rd above → scale positions 1, 4, 5 (C, F, G) = the "main cast (主要キャスト)"
• Minor chord (マイナーコード) = minor 3rd below + major 3rd above → positions 2, 3, 6 (Dm, Em, Am) = the "supporting cast (サブキャスト)"
• m-5 (m♭5) = minor 3rd + minor 3rd → position 7 (Bm-5), the diminished family

Keyboard-finding mnemonics (chant one syllable per semitone moved):

• Major triad: 「さくらんぼ（4 semitones → the 3rd）カワイイ（3 semitones → the 5th）だい好きだよ（5 semitones → the octave root — which also hands you the inversion）」 ("sakuranbo kawaii daisuki da yo" — "cherries are cute, I love them"; the syllable counts walk you from root to 3rd to 5th to octave root)
• Minor triad: 「かなしみ（3 semitones）あふれ出て（4 semitones）たえきれない（5 semitones）」 ("kanashimi afuredete taekirenai" — "sadness overflows, I can't bear it"; same walking method, minor flavor to match)

Seventh chords and altered forms, quick reference (root C examples):

Chord	Notes	Shortcut
C△7	C·E·G·B	Octave root lowered a semitone
C7	C·E·G·B♭	Octave root lowered a whole tone
Cm7 / Cm△7	Cm + B♭ / Cm + B	Same treatment applied to the minor triad
Cdim7	C·E♭·G♭·A	Adjacent intervals all minor 3rds; charts write Cdim but players play Cdim7
Caug	C·E·G♯	5th raised a semitone; adjacent intervals all major 3rds; Caug7 often substitutes for a dominant 7th
Csus4	C·F·G	The 3rd suspended up to the 4th (suspend = hung up, awaiting resolution)
C7sus4	C·F·G·B♭	Commonly used with dominant function
Cm7(♭5)	C·E♭·G♭·B♭	m7 with the 5th lowered a semitone; the II chord of the minor-key two-five — appears constantly

Chord Imagery Words (a Flavor Chart for Choosing Chords)

Chord	Image
C	Very bright, upbeat, happy
Cm	Heavy and dark, sad
C△7	Stylish (お洒落), urban, soft
C7	Quirky, unstable (in dominant function), bluesy earthiness
Cm7	Refined darkness, urbane weight
Cm△7	Mysterious, an impure dark emotion
Cdim	Eerie, anxious, sinister
Caug	Bright but drifting, slightly comical and off-balance
Csus4	Inorganic, unresolved
Cm7(♭5)	Slightly dark, unstable yet gorgeous (ゴージャス感)

Bright-to-dark ordering: C ＞ C7 ＞ Cm7 ＞ Cm (adding a 7th darkens a major chord a little; adding one brightens a minor chord a little).

Tension (テンション)

• Keep stacking thirds from the root: 1-3-5-7 = chord tones (コードトーン); scale notes stacked beyond the octave = tensions: 9th, 11th, 13th.
• Natural tensions: 9, 11, 13; altered tensions (オルタード): ♭9, ♯9, ♯11, ♭13.
• Fashion metaphor: the triad = shoes (root) + trousers (3rd) + shirt (5th); the 7th = a hat (△7 top hat / 7th flat cap); tensions = accessories (9th necklace, 11th bracelet, 13th ring) — no hat (no 7th), no accessories: without a 7th, a 9th is written add9 and a 13th is written 6th.
• Effect comparison:

Plain:        C     → A7        → Dm7    → G7         → C
With tension: C△7(9) → A7(9,♭13) → Dm7(9) → G7(♭9,♭13) → C△7(9)
              I△7(9)  VI7(9,♭13)   IIm7(9)  V7(♭9,♭13)   I△7(9)

Scales (スケール) and Modes

• A major chord takes its same-named major scale: a C chord proclaims "the sky of C" — the "birds" of the C major scale can fly anywhere without sounding off-key; switch to a D chord and you switch to the D major scale (D·E·F♯·G·A·B·C♯).
• The three minor scales (Key=Cm):
  1. Natural minor (ナチュラル・マイナー): the major scale with degrees 3, 6, 7 lowered a semitone (C D E♭ F G A♭ B♭). A natural minor = all white keys, the relative key (平行調) of C major (same key signature, same notes, different starting point).
  2. Harmonic minor (ハーモニック・マイナー): the 7th restored to a major 7th (B) = the leading tone (導音) — strong pull to resolve; side effect: the ♭6–7 gap becomes an augmented 2nd (1.5 tones), awkward to sing.
  3. Melodic minor (メロディック・マイナー): the 6th is raised too (ascending: C D E♭ F G A B), removing the augmented 2nd — smooth and singable; descending, the 6th and 7th revert to natural minor (preserving the minor darkness).
• Modal music (モード) = music with no concept of "chord progression", not relying on dominant resolution (ドミナントモーション) or cadences — "floating in the pool all day".
  • Examples: Dm7↔G7 vamp with D Dorian; a single Cm chord throughout (common in Club/Trance); a Dm7↔Em7 vamp = modal parallel motion.
  • In practice, modal accompaniment often uses voicings that obscure tonality, such as stacked fourths (4度積み). Okinawan folk songs and old Japanese folk melodies are also modal music.

4. Diatonic Chords and Functional Harmony

Diatonic Chords (ダイアトニックコード, Key=C)

Degree:  I     IIm    IIIm    IV    V     VIm    VIIm-5
Triads:  C     Dm     Em      F     G     Am     Bm-5
7ths:    C△7   Dm7    Em7     F△7   G7    Am7    Bm7(♭5)
Function:T     SD     T(or D) SD    D     T      D

• The degree types are fixed in every major key: 1 major, 2 minor, 3 minor, 4 major, 5 major, 6 minor, 7 diminished (m-5).
• Minor key (natural-minor basis): 1 minor, 2 m-5, 3 major, 4 minor, 5 minor, 6 major, 7 major; in practice V is usually swapped for a major chord to gain dominant function (in Am: Em → E).
• Textbooks usually teach with 7th chords (functions are clearer); in practice both triads and 7ths are common.
• The "family of seven" metaphor (Key=C = "the C household"; changing key = a different household with the same family structure): I△7 = the protagonist (cheeriest, most stable), IV△7 = mom (stylish and bright), V7 = dad (unstable but indispensable), VIm7/IIIm7 = the brothers (cool in a dark way, popular), IIm7 = the older sister (does the housework in mom's place = SD substitute), VIIm7(♭5) = the little sister (rarely on stage).

The Three Functions and Cadences (ケーデンス)

Function	How it sounds
Tonic (トニック, T, I)	Stable, calm, a sense of landing
Dominant (ドミナント, D, V = a fifth above the tonic)	Tension, with the power to resolve back to T
Subdominant (サブドミナント, SD, IV = a fifth below the tonic = a fourth above)	In between; can return directly to T, or push toward D for stronger tension

The skeleton of chord progressions consists of only 3 cadences:

T→D→T       I→V→I        C→G→C        (go to the turnaround point, come back to the start)
T→SD→T      I→IV→I       C→F→C        (go to the midpoint, retrace your steps)
T→SD→D→T    I→IV→V→I     C→F→G→C      (through the midpoint to the turnaround, then home)

• Roller-coaster metaphor: T = the platform, D = the drop, SD = the curve — C(T)→G7(D)→C(T) alone is monotonous; insert SD for thrills: C→F→G7→C→F→G7→F→G7→C.
• Dinner-table metaphor: T = plain rice, D = the main dish (おかず), SD = miso soup — rice alone (C C C C…) gets tiresome; alternating creates depth: C C F C | C C G C.
• 8-bar assembly (splice cadences by sharing their head/tail T):

C  | F  | C  | G  | C  | F  | G  | C
I  | IV | I  | V  | I  | IV | V  | I     = cadences ②+①+③ spliced with shared T's

Substitute Chords (代理和音) and Replacement

• Chords sharing ≥2 common tones have similar characters and can substitute for each other: IIm (Dm) → acts as SD; IIIm, VIm (Em, Am) → act as T; VIIm-5 and IIIm can also act as D (textbooks vary somewhat on assignments).
• Example: I→IV→V→I replaced as VIm→IIm→V→I (Am→Dm→G→C).
• Two-five (ツーファイブ, II–V): replace the IV of IV→V with IIm → the bass gains an ascending-fourth leap, more forceful: IIm7→V7→I (Dm7→G7→C).
• Deceptive cadence (偽終止): where T should return, go to VIm7 (Am7) or IIIm7 (Em7) instead → a floating feeling, "the song continues"; going to the major triad VI (A) = a pop variant of the Picardy cadence (ピカルディ終止).
• Combined demo (substitutes + two-five turning a simple progression into something with depth):

C → F → G7 → Am7 → F → G7 → Em7 → Am7 → Dm7 → G7 → C
I   IV   V7   VIm7  IV   V7  IIIm7  VIm7  IIm7   V7   I
(T) (SD) (D) (T-sub)(SD) (D) (T-sub)(T-sub)(←two-five→)(T)

• Harmonic rhythm (ハーモニックリズム): varying when chords change (1 per bar → change on beat 3 → one per beat). Splitting methods: ① split within the same function (I→IIIm, i.e. C→Em); ② split into SD-then-D (V split into IIm→V, i.e. Dm→G). Varying the density of chord changes = varying the sense of speed = a kind of accent.
• Complete 8-bar example (after substitutes + harmonic rhythm + voice leading):

C | F | Em | G | Am Em | F | Dm G | C
I | IV| IIIm| V| VIm IIIm| IV| IIm V| I

Voice Leading (ボイスリーディング)

• Between consecutive chords, move each voice lazily via "common tone held (unison), step (2nd), small leap (3rd)"; exploit inversions (転回形) (same notes, reordered stacking; written as slash chords C/E, G/B).
• The top voice (トップ) is most easily heard as a melodic line — design the top line's trajectory first (after voice leading, the Ōdō progression's top note drifts gently upward, the Canon progression's gently downward).
• When an inversion leaves a non-root note at the bottom, having the bass supply the root keeps the chordal identity stable.
• Traditional taboo: avoid a voice forming parallel octaves with the bass root (if needed, have the top voice descend by a 3rd instead of stepping).
• Inverting the whole voicing (flipping the top voice down an octave) changes register and color — try the same progression in different registers.

5. Classic Chord Progression Patterns (コードパターン)

The full set of 16 progressions (including bass clichés, chromatic versions, and theory commentary) is in reference.md. High-frequency patterns:

Common name	Degrees	Key=C	Character / use
Ōdō progression (王道進行, the "royal road" progression)	IV→V→IIIm→VIm	F→G→Em→Am	The J-Pop classic, standard in the sabi (サビ, the chorus/hook section); major front, minor back — bright→dark drop = drama; a loopable turnaround
Canon progression (カノン進行)	I→V→VIm→IIIm→IV→I→IIm→V	C→G→Am→Em→F→C→Dm→G	Roots descend in 5ths / ascend in 2nds — upright and stately; tours 6 diatonic chords, crystal-clear tonality
Komuro progression (小室進行)	VIm→IV→V→I	Am→F→G→C	Burned into Japanese ears by 90s J-Pop; minor start, major-tonic close
Pop-punk progression (ポップパンク進行)	I→V→VIm→IV	C→G→Am→F	Let It Be / Let It Go; variants IV→I→V→VIm, VIm→IV→I→V
Circle progression (循環コード)	I→VIm→IIm→V	C→Am→Dm→G	Loops indefinitely; second half = a two-five
Reverse circle (逆循環)	IIm→V→I→VIm	Dm→G→C→Am	Kinetic pair (IIm→V) up front, tonic-function pair bringing up the rear
Maru-sa progression (丸サ進行, the "Just The Two of Us" progression)	IV→III→VIm→Vm(→I)	F→E→Am→Gm(→C)	City pop / recent J-Pop; III and Vm = borrowed chords → floatiness and tension
Rising anticipation	IIIm→IV→V→VIm	Em→F→G→Am	Stepwise-climbing bass, mounting anticipation; swapping the opener for I/3 (C/E) is lighter
Descending ballad	VIm→V→IV→I	Am→G→F→C	Stepwise-descending bass; ballad (バラード) territory, lyrical character
Rock three-chord	I→V→IV→I	C→G→F→C	V→IV = a "weak progression", rock-specific; add 7ths to each (C7/F7/G7) = blues
Canon descending cliché	I→V/7→VIm→IIIm/5→IV→I/3→IIm→V	C→G/B→Am→Em/G→F→C/E→Dm→G	Bass walks down C-B-A-G-F-E-D-G = a bass-line cliché (ベースラインクリシェ)
Scalewise ascending cliché	I→V/2→I/3→IIm/4→I/5→IV/6→V/7→I	C→G/D→C/E→Dm/F→C/G→F/A→G/B→C

Choosing a pattern:

• The same set of chords changes mood entirely when you change the entry point; the major/minor quality of the opening and closing chords determines the overall brightness.
• You don't have to start on the tonic: IV→V→VIm→I / IIm→IIIm→IV→V (F→G→Am→C / Dm→Em→F→G).
• Hip-hop/dance/Techno/Trance/Funk often use only 1–2 chords for a whole track (modal-music thinking).
• Patterns can be used verbatim, or reworked by adding chords, applying substitutes, or inverting.

Non-Diatonic Chords (Borrowing and Color — Q&A digest)

Non-diatonic chords = borrowed chords (借用和音) temporarily taken from another key:

Device	Description	Example (Key=C)
Secondary dominant (セカンダリードミナント)	Treat a diatonic chord as a temporary tonic and precede it with its dominant 7th	A7→Dm; D/F#→G; the E in the Maru-sa progression = the V of A minor
Related IIm (リレイテッドIIm)	The II chord paired with a secondary dominant	The Gm in Gm→C7→F (= the IIm of F major)
Subdominant minor (サブドミナントマイナー)	Borrow IVm or IIm-5 from the parallel minor; a distinctive setsunasa (切なさ, bittersweet ache), common before cadences	C→Am→Fm→C (I→VIm→IVm→I)
Substitute/tritone dominant (裏ドミナント)	♭II, a tritone away from V, replaces the dominant	D♭→C instead of G7→C
Passing diminished (パッシングディミニッシュ)	Passing diminished chords give the bass chromatic ascent	C→C#m-5→Dm→D#m-5→Em
Backdoor cadence (バックドアケーデンス)	Resolution via IVm→♭VII→I	Fm→B♭→C
IV/V slash chord	Replaces V7; understated and refined (effectively V7sus4(9)), a city-pop staple	F/G→C
sus2 parallel motion	3rd replaced by the 2nd — major/minor ambiguity, no need to resolve	Csus2→E♭sus2→D♭sus2→B♭sus2

6. Writing Bass Lines

The bass has two jobs: ① supporting the chords and bridging the gaps between them; ② teaming up with the drums to complete the rhythmic groove. Three timbre families: upright bass (ウッドベース, acoustic), electric bass (エレキベース), synth bass (シンセベース).

Note-Choice Priority (Core Rule)

Strong beats where the chord changes (beats 1 and 3) MUST get the root (ルート). Everywhere else, in order of stability:
① Octave displacement of the root      ← most stable, least interference with the melody
② The chord's 5th
③ Other chord tones (the 3rd, etc.)
④ Ornament tones: passing tones (経過音, stepwise between two chord tones) /
   neighbor tones (刺しゅう音, step to a neighbor and back)
   ← ornament tones must be shorter than roots and chord tones

• Notes outside the chord — even outside the scale — cause almost no friction if treated as passing tones and placed on the offbeat one beat before a chord change (chord changes on beat 3 → place it on the offbeat of beat 2). But keep the basic shape as the core and use them only locally, or the accents stop standing out.
• A bass that avoids roots (continuous inversions) → thinner stability, more floatiness; can be done deliberately; notate the inverted bass in the chord symbol (G/B, C/G).
• A leaping bass line = an energetic impression; a smooth stepwise line = a settled impression. Choose by style. ① is simple and stays out of the melody's way; ④ turns the bass into something close to "a melody with motion" — good for fill positions.

Rhythm and Duration

• Basic principle: the bass sounds at the same moments as the Kick — aligning the low-end weight creates unity. Essential for acoustic-style timbres; electronic styles may deliberately decouple.
• Letting the bass move independently where there is no Kick (the link into the next bar, positions matching fills) = speed within unity.
• Three Duration levels:

Level	Feel	Term
100% (no gaps)	Full, dignified, heavy	Tenuto (テヌート)
80%	Balanced — clear yet weighty (default recommendation)	≈ a fuller mezzo-staccato (メゾスタッカート)
50%	Crisp and light, low rhythmic gravity	Staccato (スタッカート)

　　In practice: set the whole track to 80% as a base, then shorten individual local notes to 50% → the groove gains dimension.

• Genre-defining bass patterns: dense 16th-note roots + chromatic approach tones at slow tempo = Funk; octave alternation of roots and passing tones at fast tempo = House/Techno/Disco. Same chord progression, different bass pattern = different genre.

7. Chord Backing (バッキング/Comping)

• Backing (バッキング) = the chordal accompaniment (piano/guitar); at this stage do only the most minimal comping (コンピング) — complex arpeggios (アルペジオ) and the like belong to arranging.
• Two timing relationships with drums and bass: offset = staggered accents → smooth flow, continuous drive; aligned = coinciding accents → the kime (キメ, an all-hands unison accent hit) effect, suited to section-boundary bars.
• Afterwards, balance the volumes of the drum/bass/chord tracks, aiming to leave clearly audible space for the upcoming melody.

8. Melody Writing (Six Steps)

A melody = a succession of clearly pitched notes arranged in time (vertical axis: pitch × horizontal axis: rhythm); the "protagonist" that gets remembered on one listen.

① Timbre and Range

• Avoid the piano/guitar already used in the backing; choose a timbre that sustains (vocal-like sounds, winds, strings, Synth Lead).
• Place it in a register above the chords (separating registers is the easiest way to keep it distinct at the beginner stage).
• Singable range guideline: one octave to one octave + a 5th (e.g. lowest note G3 → highest around D5).

② Restrict to the Pentatonic Scale (ペンタトニックスケール)

• Construction: stack 5ths upward from C (C→G→D→A→E) and fold into one octave = C·D·E·G·A (do-re-mi-sol-la) = the major pentatonic (scale degrees 4 and 7 removed).
• Removing F and B eliminates the two semitone pairs E–F and B–C → almost no clashes with the chords, friendly and memorable (universal from folk song to modern pop; example: 《蛍の光》).
• Fine print: in Key=C, over Em7 and G7, just avoid the note C (do) and everything else works.
• Pentatonic vs. heptatonic (ダイアトニックスケール, including F and B): pentatonic is simple and punchy, minimally chord-dependent; the seven-note scale is nuanced and can express setsunasa (切なさ, bittersweet ache) — good for ballads. A melody that deliberately leans on F and B "weeps" more. Switching between the two is itself usable as section/phrase contrast.
• Starter exercise (anti-writer's-block): first play with just 1 note (pick from D/E/G/A, e.g. E) in 8th-note units, free lengths and timing, over the whole progression — confirm it never sounds "off" no matter which chord it lands on; then freely combine the 4 notes (including different octaves) to get the pentatonic's characteristic friendly phrases.

③ Draw the Outline (アウトライン)

• In 2- or 4-beat units, connect only the "center note of each phrase" to form an outline; survey the whole before refining details.
• Psychological effect of direction: ascending = tension rises; descending = tension releases; holding (same note) = tension sustained.
• 5 basic shapes: uphill / downhill / mountain (rise then fall) / valley (fall then rise) / flat; an 8-bar melody = a mixture of these shapes = the melody's "story arc".
• Adjacent notes (隣接音) (neighbors on the pentatonic: do↔re↔mi↔sol↔la↔do) = gentle and calm; distant notes (遠隔音) (2+ positions apart) = steep, creating a sense of accent. (Mi→sol and la→do are leaps by interval, but on the pentatonic they may be treated as steps.)
• Only adjacent → monotonous and plain; only distant → scattered and unfocused. The balance of the two is the key to a rich melody.
• Outline worked example (8 bars over C|F|Em|G|Am Em|F|Dm G|C):

First connect 2–4-beat long tones using only adjacent motion/holds: E4 → G4 → A4 → G4 … (amble through bars 1–4)
From bar 5, climb stepwise E4→G4→A4→C5→D5 to the peak D5, then settle back   = a mountain-shaped story line
Then convert local spots to distant notes for accents: e.g. bar 4 A4→D4 big drop, bar 7 A4→D5 leap up

④ Vertical Ornaments (4 Patterns)

Add up-and-down "ripples" around each center note (still within the pentatonic):

1. Center note → upper/lower adjacent note → back to the center note (= neighbor tone, 刺しゅう音)
2. Fill in the staircase toward the next center note in the same direction (turning a leap into steps) (= passing tone, 経過音)
3. Step the opposite way first, then leap across (= escape tone, 逸音)
4. Start from the upper/lower adjacent note and fall onto the center note (= appoggiatura, 倚音)

Too much ornamentation makes the impression diffuse — how much of the original outline to preserve is a matter of balance.

⑤ Horizontal Adjustments (4 Rhythm Patterns)

1. Shorten a phrase's final note to create a rest = a breathing (ブレス) point, producing phrase segmentation — a rest before the next phrase begins is crucial.
2. Add rests at a phrase's start or middle: an opening rest creates speed (a kind of accent); mid-phrase rests chop the phrase into easily-heard chunks.
3. Within a bar, shift onsets and change the balance of note lengths: lengthened notes feel "heavy", shortened notes "light" → the rhythmic center of gravity and sense of speed change.
4. Across the barline: pull the opening note earlier into the previous bar's offbeat (anticipation, アンティシペーション), or let the final note sustain past the barline — moving a strong-beat note to a weak-beat timing = a powerful rhythmic accent.

③ and ④ together are called syncopation (シンコペーション). Accents work only by contrast with "flat, unaccented phrases" — don't add them everywhere.

⑥ Motif (モティーフ) and Phrase Construction

Structural hierarchy (fractal):

Sub-motif (部分動機, ≈1 bar) ⊂ Motif (動機/モティーフ, ≥2 notes, ≈2 bars) ⊂ Small phrase (小楽節, 4 bars) ⊂ Large phrase/section (大楽節/セクション, 8 bars)

• Two features that make motifs recognizable as "the same": pitch contour + rhythm pattern. Classic examples: 《さくらさくら》 = exact motif repetition → similar variation; 《ちょうちょ》 = pitch-varied repetition + rhythm-only repetition.
• Three principles of phrase construction:
  • Repetition (反復): even exact repetition works — the changing chords underneath will carry the same motif (the listener's attention shifts to the harmony).
  • Development (展開): similar variation — transposed repetition, augmentation/diminution (拡大・縮小) of rhythm/intervals, adding/removing notes, fragmentation (分裂・断片化), retrograde (逆行), mirror inversion (鏡写し) (analysis of 《春の小川》); development also handles the phrase's "close/wrap-up (収束/締め)" = a cadential change at the phrase end (e.g. an obedient stepwise descent) + a rest on beat 4.
  • Contrast (対比): joining motifs of different character (bars 1→2 of 《もみじ》 contain 3 contrast points: rhythm, contour, and distant notes). Four contrast parameters: ① note-length density ② contour direction/shape ③ adjacent vs. distant ④ expected accents vs. syncopation; a compromise style = repeat the rhythm exactly and contrast only the contour; you can also contrast pitch material (first 2 bars pentatonic, next 2 heptatonic).
• Three schemes for the 8 bars (first 4 bars = before the turnaround, last 4 = after):

First half	Second half	Resulting impression
Repetition	More repetition / development	Highly repetitive, easiest to remember
Repetition	Contrast	A different story in the second half, strong sense of closure
Contrast	Repetition / development	One big flow across both halves, relaxed and unhurried

• Marathon metaphor: the end of bar 4 = the turnaround point; the second half can "keep the pace to the finish / change the mood entirely / recall the opening impression near the goal" (e.g. the last 2 bars of 《大きな栗の木の下で》 repeat the opening exactly → a sense of complete closure).

9. Section Design (One Chorus-Cycle)

Terminology Map

Japanese common name	Formal name	Notes
Sabi (サビ)	Chorus (コーラス) / Theme (主題)	The chorus/hook — the most essential 8-bar section
A-melo (Aメロ)	Verse (ヴァース)	The verse; Western pop often goes Verse→Chorus directly
B-melo (Bメロ)	PreChorus (プレコーラス) / Bridge (ブリッジ)	The characteristically Japanese middle section
C-melo (Cメロ)	A kind of Bridge	A brand-new melodic section inserted before the final sabi
Intro (イントロ)	Introduction (イントロダクション)	The intro
Solo (ソロ)	Interlude/Solo	The instrumental break
Outro (アウトロ)	Ending (エンディング)	The outro (アウトロ is wasei-eigo, made-in-Japan English)

• 1 chorus-cycle (1コーラス, "1番" = first verse-cycle) = A-melo → B-melo → sabi = the main sections (メインセクション); instrumental sections (Intro/Solo/Outro) = side sections (サイドセクション).
• Typical full-song structure:

Intro → 1A → 1B → 1sabi → 2A → 2B → 2sabi → Solo → (C-melo →) final sabi → Outro

• Variants: atama-sabi (頭サビ, opening directly with the chorus): sabi→1A→1B→1sabi→…; in the short-video era, the Intro and Solo are often omitted. Sections default to 8 bars but bars may be added/removed — even just 2 beats.
• "Ō-sabi (大サビ)" has two meanings: usually the final sabi; some industry usage means the C-melo (in which case the final sabi is called "rasu-sabi (ラスサビ, last sabi)").
• EDM section system: Intro → Verse A → Buildup A → Drop A → Verse B (Breakdown) → Buildup B → Drop B → Outro. Buildup arranging devices: downlifter (ダウンリフター, opening descending FX) → snare roll (スネアロール, accelerating snare hits) → riser (ライザー, ascending FX) → Break (2 beats–1 bar of silence to charge up before the climax). The Drop = the sabi position — often vocal-free with a Synth Lead as the protagonist.

Inter-Section Contrast Principles

Between sections, make one contrasting change in each of the three great elements:

• Rhythm: change the drum pattern;
• Harmony: change the chord progression; design which function each section departs from and lands on (very effective); place modulation (転調) at section boundaries — the classic being a key change into the final sabi;
• Melody — the six contrast tools:
  1. Note-length density (rhythmic contrast)
  2. Contour direction and shape
  3. Stepwise vs. leaping
  4. Expected accents vs. syncopation
  5. Pentatonic vs. heptatonic scale
  6. Vocal entry position: on the downbeat (ジャスト) / after the strong beat (rest first — e.g. 《茶摘み》) / pickup (弱起, アウフタクト/ピックアップ, jumping in from the previous bar — e.g. 《大きな古時計》) — changes the melody's sense of speed.
• Adding/removing instruments, widening/narrowing register, and volume changes (arranging territory) are equally powerful mood movers. At the section level, the same "repetition × contrast" builds the story of the entire song.

Lyric-Writing Notes (from the Composer's Perspective)

• Aim for "lyrics (作詞, リリック)" rather than "poetry (作詩, ポエム)": plan the development and contrast of content/scenes/themes per section.
• Jiashi (字脚, syllable-count footing): verse 1 and verse 2 must keep nearly identical syllable counts to fit the same melody.
• End-of-line rhyme (押韻) is effective; keep the natural Japanese pitch accent (イントネーション) aligned with the melodic contour — word choice affects the melody's rhythmic feel.
• Rhetoric: repetition (memorable), inversion (impact), metaphor (message); humming/scat/shout syllables like 「アー」「ラ・ラ・ラ」「フゥ」 are fair game — use them freely.

10. Quick-Reference Card

Songwriting checklist:
□ Drums: three-piece 8-beat? Velocity (HH alternating / Snare hard on 2·4 / Kick strong on beat 1)?
      Small fill in bar 4, big fill + Toms in bar 8? Crash at section start? HH silent during fills?
□ Chords: T→SD→D→T skeleton? Picked from the pattern table? Substitute chords / harmonic-rhythm variation?
      Voice leading (common tones held · nearest motion · top-note line)?
□ Bass: roots on strong beats? Locked to the Kick? Duration 80% baseline with local 50%?
      Ornament tones short and on the offbeat before chord changes?
□ Backing: offset (flow) or aligned (kime)? Three-track balance leaving space for the melody?
□ Melody: pentatonic start? 5 outline shapes + adjacent/distant balance? 4 vertical-ornament patterns?
      Rests for breathing? Motif repetition × contrast?
□ Sections: one change per element between adjacent sections? Vocal entry position varied?
      Modulate for the final sabi or not?
The universal keyword = balance: ornament vs. original outline, adjacent vs. distant,
syncopated vs. flat, repetition vs. contrast
—— accents and personality only work by contrast with the "plain parts".

Key-change workflow: ① write the progression in degrees in C major → ② use the 12-key table in reference.md to convert the degrees into the target key's chord names → ③ re-connect the voices by nearest motion per voice-leading principles. Degree ("jersey number") thinking is the lingua franca for transposition and transcription by ear (耳コピ).

Beyond this skill's scope: arpeggiated backing and sound design, instrumentation, modulation techniques, and detailed tension voicings belong to arranging (アレンジ); minor-key-specific progressions and melody harmonization techniques are covered in later skills in this series.

Detailed reference material (all 16 chord progressions, 12-key diatonic chord tables, Japanese-English glossary, EDM terms) → reference.md