Scale degrees · G major
The ♭9 of G is A♭
The ♭9 (flat nine, written b9) of G is A♭ (A flat): a minor ninth above the root.
G — the root, 1A♭ — the ♭9
How to find it
A 9th is a 2nd an octave up, so it takes the 2nd's letter: G, A.
Then the sound: a minor ninth is 13 semitones above G, and the A that is 13 semitones up is A♭.
That is why it is A♭ and not G♯: G♯ is the same key on the piano, but from G it would be an 8th, not a 9th.
Where you meet it
The ♭9 is the first altered tension on a dominant chord. It is the ♭2 an octave up, written as a 9 because it sits above the chord.
In G7♭9:
G · B · D · F · A♭
The ♭9 in every key
| Key | The ♭9 |
|---|---|
| C | D♭ |
| G | A♭ |
| D | E♭ |
| A | B♭ |
| E | F |
| B | C |
| F♯ | G |
| D♭ | E𝄫 |
| A♭ | B𝄫 |
| E♭ | F♭ |
| B♭ | C♭ |
| F | G♭ |
Every degree of G
Free on iPhone and Android
Name it before
you can count it.
Improvy trains every degree in all 12 keys — the 3, the ♭7, the ♯11 — until you see the note without working it out. A few minutes a day. Free to start; Pro is one payment, never a subscription.
Or try the 60-second test in your browser