A# Lydian Mode: Notes, Chords and How to Play It
Lydian is the major scale's dreamy cousin. It is bright and open like an ordinary major scale, but one note is nudged upward, and that small change makes the music feel like it's floating. You hear this sound all the time in film scores when the camera pans over something vast and beautiful. Here we'll learn it in the key of A#: the notes, why it sounds the way it does, the chords that come from it, and where to put your fingers on the neck. One thing up front: the spelling of this key looks strange on paper. Don't worry, there's a simple explanation, and it won't change a thing about how you play it.
The Notes of A# Lydian
A# Lydian has seven notes:
A#, B#, C##, D##, E#, F##, G##
If you've never seen a double sharp (##) before, it simply means "raise this note by two half steps." A half step is the distance of one fret on the guitar, so a double sharp moves a note up two frets from its natural position. Notes like B# and E# can also look odd, since they sit on the same fret as other note names. They're spelled this way so that every letter from A to G appears exactly once, which keeps the theory tidy.
A friendly word about spelling
A# Lydian is what musicians call a theoretical key, because writing it properly needs double sharps. In real life, nobody reads music in this key. Players write it as Bb Lydian, which has a key signature of just one flat and sounds exactly the same. A# and Bb are the same fret, the same pitch, the same sound. So if you play A# Lydian, you're playing Bb Lydian. The fingerings, the sound and the chords are identical; only the names on paper change. Learning the A# spelling is a great theory workout, but if you're jamming with friends, call it Bb Lydian and everyone will be on the same page.
How the Step Pattern Builds the Scale
Every scale is a recipe of steps. A whole step is two frets; a half step is one fret. Lydian's pattern is:
W - W - W - H - W - W - H
Starting on A#, here's how it unfolds:
- A# up a whole step to B#
- B# up a whole step to C##
- C## up a whole step to D##
- D## up a half step to E#
- E# up a whole step to F##
- F## up a whole step to G##
- G## up a half step back home to A#
Notice the three whole steps in a row at the start. That stretch is the secret ingredient, and it leads us straight to Lydian's signature note.
What Makes It Sound Dreamy
Compared with an ordinary major scale, Lydian has one difference: a raised (sharp) 4th. The formula is 1, 2, 3, #4, 5, 6, 7. In A#, that #4 is D##.
In a regular major scale, the 4th wants to fall down to the 3rd. It has a little tug to it, a sense of tension. Raising it removes that pull. Instead of leaning, the melody seems to hover. That's the floating, wide-open quality people love.
To hear it, hold an A# note or chord ringing, then play D## over it. Listen for that shimmering, slightly unexpected brightness. When you improvise, land on D## now and then and let it sustain. That's the moment the music stops sounding "just major" and starts sounding Lydian.
Lydian shares its notes with E# major (E#, F##, G##, A#, B#, C##, D##). The difference is the home base: Lydian starts and resolves on A#, so A# feels like the centre of gravity.
Chords From A# Lydian
Building a chord on each note of the scale gives you these:
- I: A# (A#-C##-E#) / A#maj7
- II: B# (B#-D##-F##) / B#7
- iii: C##m (C##-E#-G##) / C##m7
- #iv°: D##dim (D##-F##-A#) / D##m7b5
- V: E# (E#-G##-B#) / E#maj7
- vi: F##m (F##-A#-C##) / F##m7
- vii: G##m (G##-B#-D##) / G##m7
The star of the show is the II chord, B#. In a normal major key the chord on the 2nd step is minor, but in Lydian it's major, because it contains that raised 4th, D##. A major I chord moving to a major II chord is the classic Lydian sound.
A progression to jam over
Try a simple two-chord vamp:
A#maj7 to B# (two bars each), repeated
Strum it slowly and let it breathe. Record it or loop it, then improvise over it with the scale. Aim to start and end phrases on A#, and lean on D## to bring out the colour. For a bit more movement, try A# - B# - G##m - A#.
Finding the Root on the Neck
In standard tuning, your A# root notes are here:
- Low E (6th) string: frets 6 and 18
- A (5th) string: frets 1 and 13
The 6th fret of the low E string is a comfortable starting point. Play A# there, then walk up the step pattern: two frets, two frets, two frets, one fret, and so on, shifting to the next string when the stretch gets awkward. The 1st fret on the A string gives you a low, warm root that sounds great for slow, spacious melodies.
Your Practice Plan
Spend five minutes today simply playing the scale up and down from the 6th fret, saying each note name out loud. Then loop that A#maj7 to B# vamp and improvise for a few minutes, using only three notes at first: A#, C## and D##. Listen for the moment D## lifts everything off the ground. Once you feel it, you'll start hearing Lydian in film music everywhere, and you'll be able to make that sound yourself.
For the bigger picture, read The Lydian Mode.