Lydian is the fourth mode of the major scale — when the 4th scale degree functions as the tonic on the guitar. Because it centers on a major chord, it’s considered a major key. Rarely do you hear a song that’s completely in Lydian mode. Instead, this mode usually occurs only temporarily in a song, until the music moves to a more stable tonic like I.
Here you see what happens to the G major scale when you reorganize its notes and chords, beginning with the 4th degree, C, to produce C Lydian mode:
G major
1-2-3-4-5-6-7
G-A-B-C-D-E-F♯
I-ii-iii-IV-V-vi-vii♭ó5
G-Am-Bm-C-D-Em-F♯m♭ó5
C Lydian
1-2-3-♯4-5-6-7
C-D-E-F♯-G-A-B
I-II-iii-♯iv♭ó5-V-vi-vii
C-D-Em-F♯m♭ó5-G-Am-Bm
The most defining characteristic of Lydian mode is its sharpened 4th, which is why many musicians think of it as a major scale with a sharpened 4th. You see C Lydian taken from its parent major scale, G.
You can play C Lydian anywhere on the fretboard as long as you use notes and chords from the G major scale and center on C. You can also move the pattern around the fretboard to play Lydian mode in other keys.
Here, you are put in a new major scale pattern that begins on the 5th string. Here, the parent major scale is C and the mode is F Lydian. Again, this is just a starting point. You find the same notes and chords elsewhere on the fretboard, and you can move this pattern around to play in other keys.
Here are a few sample chord progressions and songs based on the 4th degree of the major scale:
“Dreams” by Fleetwood Mac
Fmaj7-G6
I-II in F Lydian (IV-V in the C major scale)
“Just Remember I Love You” by Firefall
Fmaj7-G6
I-II in F Lydian (IV-V in the C major scale)
“Jane Says” by Jane’s Addiction
G-A
I-II in G Lydian (IV-V in the D major scale)
“Here Comes my Girl” by Tom Petty
A-B
I-II in A Lydian (IV-V in the E major scale)
“Man on the Moon” by R.E.M.
C-D
I-II in C Lydian (IV-V in the G major scale)
“Hey Jealousy” by Gin Blossoms
D-E-F♯m-E
I-II-iii-II in D Lydian (IV-V-vi-V in the A major scale)
“Space Oddity” by David Bowie
Fmaj7-Em
I-vii in F Lydian (IV-iii in the C major scale)