interval
B♭ minor second
B♭lowerC♭upperm21 half steps
One half step, written as a second: the smallest distance between two notes with different letters.
On the keyboard
What is true of it
B♭ up a minor second is C♭: 1 half step, and 2 letters counting both ends.
Turn it upside down — put the B♭ on top — and it becomes a major seventh. The two numbers always add to nine, and the two sizes to twelve.
It is a dissonance.
Every interval on B♭
B♭ → Cmajor second · dissonanceB♭ → D♭minor third · imperfect consonanceB♭ → Dmajor third · imperfect consonanceB♭ → E♭perfect fourth · perfect consonanceB♭ → Eaugmented fourth · dissonanceB♭ → F♭diminished fifth · dissonanceB♭ → Fperfect fifth · perfect consonanceB♭ → G♭minor sixth · imperfect consonanceB♭ → Gmajor sixth · imperfect consonanceB♭ → A♭minor seventh · dissonanceB♭ → Amajor seventh · dissonance