interval
D major third
DlowerF♯upperM34 half steps
Four half steps. The interval that makes a triad major.
On the keyboard
What is true of it
D up a major third is F♯: 4 half steps, and 3 letters counting both ends.
Turn it upside down — put the D on top — and it becomes a minor sixth. 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 → 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