The formula for the Lydian Agmented scale is:
R - 2 - 3 - #4 - #5 - 6 - 7
You can see this scale is similar to the major scale Lydian mode, the only difference being the #5. The term ‘Lydian’ suggests a #4 and ‘Augmented’ a #5 (#11).
Possible extensions/tensions: 9, #11, 13
- Lydian Augmented chords can be used instead of a
- I chord.
- V chord.
We can borrow this chord (maj7#5) and force it on to a I chord. The tonality is quite dissonant but it works. When you think about it, we can already play Lydian over a I chord. This is just an extension to that.
You can also substitute your V chords for maj7#5 chords.