Scale degrees · D major
The ♭13 of D is B♭
The ♭13 (flat thirteen, written b13) of D is B♭ (B flat): a minor thirteenth above the root.
D — the root, 1B♭ — the ♭13
How to find it
A 13th is a 6th an octave up, so it takes the 6th's letter: D, E, F, G, A, B.
Then the sound: a minor thirteenth is 20 semitones above D, and the B that is 20 semitones up is B♭.
That is why it is B♭ and not A♯: A♯ is the same key on the piano, but from D it would be a 12th, not a 13th.
Where you meet it
The ♭13 is an altered tension of the dominant chord, one of the notes of the altered scale.
In D7♭13:
D · F♯ · A · C · B♭
The ♭13 in every key
| Key | The ♭13 |
|---|---|
| C | A♭ |
| G | E♭ |
| D | B♭ |
| A | F |
| E | C |
| B | G |
| F♯ | D |
| D♭ | B𝄫 |
| A♭ | F♭ |
| E♭ | C♭ |
| B♭ | G♭ |
| F | D♭ |
Every degree of D
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