On the guitar, Lydian is the fourth mode of the major scale, and the sound that’s created when the 4th scale degree functions as the tonic. Because it features a major 3rd and centers on a major chord, it’s considered a major mode.
Drawing from the G major scale, Lydian mode looks like this:
G major
1-2-3-4-5-6-7
G-A-B-C-D-E-Fs
I-ii-iii-IV-V-vi-viif5
G-Am-Bm-C-D-Em-Fsmf5
C Lydian
1-2-3-s4-5-6-7
C-D-E-Fs-G-A-B
I-II-iii-sivf5-V-vi-vii
C-D-Em-Fsmf5-G-Am-Bm
Lydian can be thought of as a major scale with a raised 4th, it’s most defining characteristic. This s4th causes the 2nd chord to be major. A typical Lydian progression is I-II, two major chords right in a row.
Here is how to view the fretboard in C Lydian mode, using, of course, the very same notes and chords you use for G major. The only difference is that the 4th degree, C, is now the tonic and counted as number 1. If you want to play a Lydian scale, play 1 to 1.
This is just one way to view the fretboard. You can use other positions, patterns, and chord shapes to play in this mode too. As long as you use notes and chords from the G major scale and the 4th degree, C, functions as the tonic, the mode is C Lydian. You can play in other Lydian keys by centering music on the 4th degree of other major scales.
In order to properly produce the Lydian sound, you need to use some type of accompaniment, like the one shown in here. This IV-V chord progression in G becomes I-II when you start on C.
You can play along with G major scale notes to produce the sound of C Lydian mode in Chapter 13, Audio Track 17: C Lydian Play-Along Track.
Because Lydian mode centers on a major chord, most lead guitar players prefer to approach it with major pentatonic scale patterns. You can see how to put together C major pentatonic and G major scale patterns here.
You can think of Lydian mode as being the major pentatonic with an added s4th and 7th. Coincidentally, C Lydian and A Dorian use the same pattern combinations because C major and A minor pentatonic are relative to one another, and they’re both mixed with the G major scale.
Although you don’t need to master all these patterns, it is recommended that you at least play through the combination set in C major pentatonic pattern 1 beginning at the 5th fret of the 6th string (it starts on A; C is located at the 8th fret).
Notice that instead of having you play past the 15th fret for pentatonic pattern 5, you are positioned an octave lower on the fretboard. The key of C Lydian is just a starting point. Move the same patterns around to play Lydian mode in other keys.
Any time a piece of music uses the major scale and centers on the 4th degree, chord IV, it’s Lydian mode. Some song examples that are either entirely based in Lydian mode or at least have a Lydian section include the following:
“Man on the Moon” by R.E.M. (C Lydian)
“Dreams” by Fleetwood Mac (F Lydian)
“Just Remember I Love You” by Firefall (F Lydian)
“Jane Says” by Jane’s Addiction (G Lydian)
“Here Comes my Girl” by Tom Petty (A Lydian)
“Hey Jealousy” by Gin Blossoms (D Lydian)
“Space Oddity” by David Bowie (F Lydian)
“Freewill” by Rush (F Lydian)
Because of its unresolved sound, Lydian mode quickly dissipates when you move to a more stable tonic, such as the I chord in the parent major scale. In these songs, it’s very common for a section to focus on a major scale’s IV chord, creating a Lydian mode, followed by another section that centers on chord I, creating an Ionian mode. This shift often happens between a verse and chorus.