interval
D♯ perfect fourth
D♯lowerG♯upperP45 half steps
Five half steps. Turned upside down it becomes a perfect fifth.
On the keyboard
What is true of it
D♯ up a perfect fourth is G♯: 5 half steps, and 4 letters counting both ends.
Turn it upside down — put the D♯ on top — and it becomes a perfect fifth. The two numbers always add to nine, and the two sizes to twelve.
It is a perfect consonance.
Every interval on D♯
D♯ → Eminor second · dissonanceD♯ → E♯major second · dissonanceD♯ → F♯minor third · imperfect consonanceD♯ → F𝄪major third · imperfect consonanceD♯ → G𝄪augmented fourth · dissonanceD♯ → Adiminished fifth · dissonanceD♯ → A♯perfect fifth · perfect consonanceD♯ → Bminor sixth · imperfect consonanceD♯ → B♯major sixth · imperfect consonanceD♯ → C♯minor seventh · dissonanceD♯ → C𝄪major seventh · dissonance