Scale degrees · A major

The ♯11 of A is D♯

The ♯11 (sharp eleven, written #11) of A is D♯ (D sharp): an augmented eleventh above the root.

A — the root, 1D♯ — the ♯11

How to find it

An 11th is a 4th an octave up, so it takes the 4th's letter: A, B, C, D.

Then the sound: an augmented eleventh is 18 semitones above A, and the D that is 18 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 12th, not an 11th.

Where you meet it

The ♯11 is the Lydian tension: the bright, open colour of maj7♯11 and of the Lydian dominant 7♯11.

In Amaj7♯11:

A · C♯ · E · G♯ · D♯

The ♯11 in every key

KeyThe ♯11
CF♯
GC♯
DG♯
AD♯
EA♯
BE♯
F♯B♯
D♭G
A♭D
E♭A
B♭E
FB

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