A Dorian ♭5 Scale
A Dorian ♭5 contains 7 notes: A, B, C, D, E♭, F♯, G. It has 1 sharp: F♯. The step pattern is W–H–W–H–W+H–H–W.
A minor mode with a diminished quality from its flat 5th, but warmer than standard Locrian thanks to Dorian's natural 6th. It sits in an unusual middle ground between groove and instability.
The formula is 1, 2, b3, 4, b5, 6, b7. The natural 6th provides brightness, but the b5 removes the stable perfect 5th that anchors most minor modes. This combination is unusual and creates interesting melodic movement, especially when used over m7b5 chords where you want a warmer sound than Locrian.
Use your harmonic major shapes rooted on the 2nd degree. The natural 6th gives you a strong melodic note that standard Locrian lacks. Best applied over half-diminished chords in jazz progressions where you want to avoid Locrian's extreme darkness.