interval
D minor sixth
DlowerB♭upperm68 half steps
Eight half steps. The major third turned upside down.
On the keyboard
What is true of it
D up a minor sixth is B♭: 8 half steps, and 6 letters counting both ends.
Turn it upside down — put the D on top — and it becomes a major third. The two numbers always add to nine, and the two sizes to twelve.
It is a imperfect consonance.
Every interval on D
D → E♭minor second · dissonanceD → Emajor second · dissonanceD → Fminor third · imperfect consonanceD → F♯major third · imperfect consonanceD → Gperfect fourth · perfect consonanceD → G♯augmented fourth · dissonanceD → A♭diminished fifth · dissonanceD → Aperfect fifth · perfect consonanceD → Bmajor sixth · imperfect consonanceD → Cminor seventh · dissonanceD → C♯major seventh · dissonance