B♭ Lydian ♭3 Scale
B♭ Lydian ♭3 contains 7 notes: B♭, C, D♭, E, F, G, A. It has 2 flats: B♭, D♭. The step pattern is W–H–W+H–H–W–W–H.
A paradoxical mode that's minor (b3) but somehow feels uplifting. The raised 4th, natural 6th, and natural 7th inject so much brightness into the minor framework that it sounds like a more exotic, sophisticated cousin of Dorian.
The formula is 1, 2, b3, #4, 5, 6, 7. The b3 establishes minor quality while the #4, natural 6, and natural 7 push strongly toward brightness. It works over minor-major 7th chords with a #11 extension and can add real sophistication to modal jazz compositions.
An excellent alternative to standard Dorian when you want more exotic flavor over minor chords. Emphasize the #4 and natural 7 — they're what distinguish this from regular Dorian. Use harmonic major shapes rooted on the 4th degree.