Altered guitar scale
See the Altered scale on a guitar fretboard, learn its notes and degrees, and practice it in any key.
What it is
The seventh mode of melodic minor, also called Super Locrian. Every colour note of a dominant chord is altered (♭9, ♯9, ♯11, ♭13): very tense.
How to use it
Play it over a dominant 7 chord that resolves down a fifth, especially the V7 of a minor ii to V to i. The tension asks to be resolved on the next chord.