The Lydian scale or Lydian mode is a major scale that begins on on the fourth note of a major scale. A Lydian scale is a type of of major scale with an augmented (or sharp) fourth. The third note of the scale is major, as opposed to the Phrygian mode, Aeolian or Locrian where their third note is flat (a minor third). The augmented 4th gives playing the Lydian scale the qualities, sound and texture of a major scale but with a little bit more ‘happiness’ and light added to it.
Let’s first look at a C major scale, the key with no sharps or flats. The 4th note in the scale is shown in green:
Based off the C major scale, the F Lydian scale would look like this. The affected note is in red:
*Update: B# should be B. The image will be swapped out shortly.
Like with other modal studies, the key did not change. Only notes that are modified from the mode itself change. If there were additional keys and more modifications going on, those would happen first then you would apply the changes to the given notes.
For example, let’s say we were now in the key of F. There is one flat: Bb:
We’ve applied our key signature related changes. Now let’s identify the 4th note in the scale (Bb) and craft the Lydian mode:
While we are working in a flat key versus a sharp key like G major, the Lydian scale modifications still rule: the 4th note of the scale becomes augmented.
You might be able to apply notes from a Lydian scale in places where you might find yourself using a basic major scale.
Examine the examples below and see if you can identify what the Lydian scale would be: