Ab Lydian

The Ab Lydian mode (also written G#) — Ab Bb C D Eb F G — shown across the guitar neck.

Also written G# Lydian. G# and Ab are the same pitch, though spelling it from G# would need double accidentals (G# A# B# C## D# E# F##), which is why Ab is the name in use.

Swipe the neck sideways to see the higher frets.

Ab Lydian is the major scale with one note changed — the #4, D. That single note is what the mode sounds like; lean on it and the colour is obvious, avoid it and you are just playing major.

The tool shows this from its parent key, Eb major, with Ab marked as where Lydian begins, the same seven notes centered on Eb.