C# Harmonic Minor Scale
C sharp harmonic minor runs C sharp, D sharp, E, F sharp, G sharp, A, B sharp and back to C sharp. B sharp is played on the piano key labeled C. Its name shows that the seventh degree B has been raised by a half step.
- Notes: C sharp-D sharp-E-F sharp-G sharp-A-B sharp
- Raised seventh: B sharp
- Key signature: four sharps
Why call it B sharp?
C sharp natural minor uses B natural, a whole step below C sharp. Raise B by one semitone and it lands on the C key. Writing B sharp preserves B as scale degree 7 and makes the change from natural minor readable. Calling it C natural would place two C names next to each other in the written scale.
A to B sharp spans three semitones. Play G sharp-A-B sharp-C sharp slowly: the wide middle gap and close ending are both part of the harmonic-minor sound.
What does it change in a chord?
The natural-minor fifth chord is G sharp-B-D sharp, or G sharp minor. B sharp turns it into G sharp-B sharp-D sharp, or G sharp major. Play both before C sharp-E-G sharp. Follow the B-sharp-to-C-sharp movement in the second version.
The four-sharp C-sharp-minor key signature remains F sharp, C sharp, G sharp and D sharp. B sharp appears as an accidental when the harmony or melody calls for it.
Practice the written and played versions
Say "B sharp" while pressing the C key, then move to C sharp. Repeat over a C-sharp-minor chord. The point is to connect a surprising written name to a very simple one-key movement.