Diatonic Chord & Progression Generator
Choose a key and a scale — the seven chords that belong to it and the progressions built from them appear instantly. No chord charts to memorise.
🎹 Key & Scale
Root (key)
Scale
Major & minor
Modes
Chord typeStep pattern: W-W-H-W-W-W-HFamily: Major family
The brightest and most fundamental scale. Its diatonic chords run I ii iii IV V vi vii°.
🎼 Scale Notes — C Major
| Deg. | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|
| Note | C | D | E | F | G | A | B |
| Solfège | Do | Re | Mi | Fa | Sol | La | Ti |
| Scale degree | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
Keyboard
🎸 Diatonic Chords
Tap a chord to highlight its notes on the scale and keyboard.
| Numeral | Chord | Notes | Quality | Function |
|---|---|---|---|---|
| I | C | C · E · G | Major triad | TTonic |
| ii | Dm | D · F · A | Minor triad | SDSubdominant |
| iii | Em | E · G · B | Minor triad | TTonic |
| IV | F | F · A · C | Major triad | SDSubdominant |
| V | G | G · B · D | Major triad | DDominant |
| vi | Am | A · C · E | Minor triad | TTonic |
| vii° | Bdim | B · D · F | Diminished triad | DDominant |
🔁 Chord Progressions
Tonic → subdominant → dominant → tonic. The starting point of all harmony.
I
C
C E G
IV
F
F A C
V
G
G B D
I
C
C E G
Switch to sevenths for the jazz version of each progression.
Theory basis
- 🎼 Scale formulas: whole/half step intervals in 12-tone equal temperament
- ✍️ Note spelling: each scale uses letters A–G exactly once (the 7th of F♯ major is E♯, never F)
- 🎹 Diatonic chords: stack thirds on each scale degree for triads and sevenths
- 🔢 Roman numerals: uppercase for major/augmented, lowercase for minor/diminished, ° dim / + aug / ø half-dim 7
- 🧭 Harmonic function: degrees 1·3·6 tonic, 2·4 subdominant, 5·7 dominant
※ Real songs also use non-diatonic chords (secondary dominants, modal interchange). This tool shows the diatonic starting point.
Guide · FAQ · bal.pe.kr
See the Guide, FAQ and About pages for the theory and notation rules. Last updated 2026-08-24.