Fig. 1 · B to C#

interval

B major second

BlowerC♯upperM22 half steps

A whole step. The distance between most neighbouring notes of a major scale.

On the keyboard

BC#
Fig. 2

What is true of it

B up a major second is C♯: 2 half steps, and 2 letters counting both ends.

Turn it upside down — put the B on top — and it becomes a minor seventh. The two numbers always add to nine, and the two sizes to twelve.

It is a dissonance.

Every interval on B

B → Cminor second · dissonanceB → Dminor third · imperfect consonanceB → D♯major third · imperfect consonanceB → Eperfect fourth · perfect consonanceB → E♯augmented fourth · dissonanceB → Fdiminished fifth · dissonanceB → F♯perfect fifth · perfect consonanceB → Gminor sixth · imperfect consonanceB → G♯major sixth · imperfect consonanceB → Aminor seventh · dissonanceB → A♯major seventh · dissonance

C M2C♯ M2D♭ M2D M2D♯ M2E♭ M2E M2F M2all 204