Scale degrees · A♭ major

The ♯11 of A♭ is D

The ♯11 (sharp eleven, written #11) of A♭ (A flat, Ab) is D: 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♭, which is exactly where D is — no sharp or flat needed.

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 A♭maj7♯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