interval
D minor second
DlowerE♭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
D up a minor second is E♭: 1 half step, and 2 letters counting both ends.
Turn it upside down — put the D 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 D
D → 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 → B♭minor sixth · imperfect consonanceD → Bmajor sixth · imperfect consonanceD → Cminor seventh · dissonanceD → C♯major seventh · dissonance