C Half-Whole Diminished at a glance
The half-whole diminished is the standard scale over a dominant 7♭9 chord in jazz. Its symmetry means a phrase transposed by minor third still fits the chord, perfect for fast harmonic motion. Built on the root C, the scale takes on the specific colour and pitch range of that key - making it especially useful in genres and registers where C is a comfortable tonal centre.
| Notes | C D♭ E♭ E F♯ G A B♭ |
|---|---|
| Formula | 1P · 2m · 3m · 3M · 4A · 5P · 6M · 7m |
| Step pattern | H W H W H W H W |
C Half-Whole Diminished on the piano
Improvisation drone · C
Loop the root note as a pad to practice improvising over this scale.
On the piano C Half-Whole Diminished uses four black keys (D♭, E♭, F♯ and B♭) and four white.
C · D♭ · E♭ · E · F♯ · G · A · B♭
Play C Half-Whole Diminished on the online piano
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C Half-Whole Diminished on the guitar
C Half-Whole Diminished - fr 0–12
C Half-Whole Diminished on the staff
Notes of the C Half-Whole Diminished scale
| Degree | Note | Interval | Semitones | Hear |
|---|---|---|---|---|
| 1 | C | unison1P | 0 | |
| 2 | D♭ | minor 2nd2m | 1 | |
| 3 | E♭ | minor 3rd3m | 3 | |
| 4 | E | major 3rd3M | 4 | |
| 5 | F♯ | augmented 4th4A | 6 | |
| 6 | G | perfect 5th5P | 7 | |
| 7 | A | major 6th6M | 9 | |
| 8 | B♭ | minor 7th7m | 10 |
What makes C Half-Whole Diminished different
The half-whole diminished scale has eight notes that alternate a half step and a whole step, so its pattern repeats every minor third. That symmetry means there are only three different ones: the scale on C has the same notes as those on E♭, G♭ and A. It holds the 1, 3, 5 and ♭7 of a dominant chord plus the ♭9, ♯9 and ♯11. Its natural fifth and natural 13th are what separate it from the Altered scale over the same chord.
How to use the C Half-Whole Diminished scale
Because C Half-Whole Diminished has fewer or more than seven notes, it doesn't produce a standard set of seven diatonic triads. Instead, build chords by stacking thirds within the scale or use it as a melodic colour over chords drawn from a related diatonic key.
The half-whole diminished is the standard scale over a dominant 7♭9 chord in jazz. Its symmetry means a phrase transposed by minor third still fits the chord, perfect for fast harmonic motion.
Practice tips
Practise the scale starting from each chord tone of the underlying dominant 7♭9 (1, ♭3, ♭5, ♭♭7) — they're all four equivalent because of the symmetry, and that insight is what makes diminished playing fast and fluid.
Formula & step pattern
The C Half-Whole Diminished scale follows an eight-note symmetric scale alternating half-step then whole-step (1, ♭2, ♭3, 3, ♯4, 5, 6, ♭7). Step pattern: H - W - H - W - H - W - H - W. Intervals from the root: 1P · 2m · 3m · 3M · 4A · 5P · 6M · 7m. Memorising the formula lets you transpose the scale to any other root note quickly.
Where you will hear C Half-Whole Diminished
Start with the music described above: listen for C Half-Whole Diminished in it and transcribe a few short phrases by ear. It's the quickest way to learn how the scale sounds.
Questions people ask
What notes are in the C Half-Whole Diminished scale?
The C Half-Whole Diminished scale contains C, D♭, E♭, E, F♯, G, A and B♭.
What is the formula for the C Half-Whole Diminished scale?
C Half-Whole Diminished follows an eight-note symmetric scale alternating half-step then whole-step (1, ♭2, ♭3, 3, ♯4, 5, 6, ♭7).
Is C Half-Whole Diminished a major or minor scale?
C Half-Whole Diminished is a half-whole diminished scale. Octatonic scale alternating half then whole steps — symmetric, dissonant, the standard choice over a dominant 7♭9 chord in jazz.
What chords belong to the C Half-Whole Diminished scale?
C Half-Whole Diminished doesn't produce a standard seven-chord diatonic set. Use chords from a related diatonic scale instead.
Which genres use C Half-Whole Diminished?
The half-whole diminished is the standard scale over a dominant 7♭9 chord in jazz. Its symmetry means a phrase transposed by minor third still fits the chord, perfect for fast harmonic motion.
How do you play the C Half-Whole Diminished scale on the piano?
On the piano C Half-Whole Diminished uses four black keys (D♭, E♭, F♯ and B♭) and four white.
How do I practise the C Half-Whole Diminished scale?
Practise the scale starting from each chord tone of the underlying dominant 7♭9 (1, ♭3, ♭5, ♭♭7) — they're all four equivalent because of the symmetry, and that insight is what makes diminished playing fast and fluid.