Lydian guitar scale
See the Lydian scale on a guitar fretboard, learn its notes and degrees, and practice it in any key.
What it is
A major scale with a raised 4th. Dreamy, floating and bright, with a sense of wonder.
How to use it
Play it over a major 7 chord that lasts a while, or over the IV chord of a key. The ♯4 is the characteristic note: let it lead up to the 5th instead of staying on it.