Scale degrees · A major
The ♯4 of A is D♯
The ♯4 (sharp four, written #4) of A is D♯ (D sharp): an augmented fourth above the root.
A — the root, 1D♯ — the ♯4
How to find it
Count letters first, the root included: A, B, C, D. A 4th lands on D.
Then the sound: an augmented fourth is 6 semitones above A, and the D that is 6 semitones up is D♯.
That is why it is D♯ and not E♭: E♭ is the same key on the piano, but from A it would be a 5th, not a 4th.
Where you meet it
The ♯4 is the Lydian note, a tritone above the root. On a chord symbol it is usually written ♯11.
In the scale A Lydian:
A · B · C♯ · D♯ · E · F♯ · G♯
The ♯4 in every key
| Key | The ♯4 |
|---|---|
| C | F♯ |
| G | C♯ |
| D | G♯ |
| A | D♯ |
| E | A♯ |
| B | E♯ |
| F♯ | B♯ |
| D♭ | G |
| A♭ | D |
| E♭ | A |
| B♭ | E |
| F | B |
Every degree of A
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