For the purposes of writing music from a theory perspective, let’s take a look at where the Lydian Mode comes from. Technically, the Lydian Scale is the fourth mode of the major scale. All this means is that if you start and end a major scale on the fourth note, you’ll get the Lydian Mode. Most guitarists can understand this, but what they usually forget to learn is this: If you start a major scale on a different note, all the chords shift places too. This is why a lot of guitarists ‘know’ the modes, but have no idea how and when to actually use them.
You’re probably familiar with the diatonic sound of chords, and the roman numeral system as follows:
Your new roman numerals sequence should look like this with the basic major and minor chords:
I – II – IIIm – #IV° – V – VIIm – VIIm – I
Or like this if you’re using 7 chords:
Imaj7 – II7 – IIIm7 – #IVm7b5 – Vmaj7 – VIm7 – VIIm7 – Imaj7
If I just lost you, check out the explanation in the Understanding Modes article which shows you how to visualize this same information, but in a circular fashion.
What can you do with this information?
You can start to construct chord progressions from the point of view of F (if you’re in C major) to get that Lydian sound going. Even a two-chord vamp using the first two chords (F and G major) will evoke the Lydian sound when you start soloing over them using F Lydian.
As I mentioned, plenty of guitarists can throw on a Lydian backing track and blow over it, but few really understand why and how it works; the advantage of this being that you can actually apply it to your own playing.
The No-Theory-Required Guide
If you prefer to just dive in and make music to see what you can come up with, all you need is the following fretboard diagram, and plenty of creativity. We’re going to use the A Lydian Scale. Use the open A string as a drone or reference tone and play it with any combination of the notes in the diagram. The red notes are also As. The blue notes are the notes that define the sound of the Lydian scale. Get creative and see what you can come up with. If you stick to these notes, whatever you play will sound Lydian.