The B Phrygian scale has 7 notes: B – C – D – E – F♯ – G – A. Phrygian is a minor scale with a ♭2, one fret above the root. That dark half step gives it a Spanish, heavy feel. In Indian music it is Bhairavi thaat.
Compared with the B major scale it has ♭2 (C instead of C♯), ♭3 (D instead of D♯), ♭6 (G instead of G♯), ♭7 (A instead of A♯).
The explorer above is set to B Phrygian: the whole neck is mapped, and you can zoom into any of its 7 positions, change the labels to degrees or fingers, and hear it up, down and in patterns.