interval
G♯ perfect fourth
G♯lowerC♯upperP45 half steps
Five half steps. Turned upside down it becomes a perfect fifth.
On the keyboard
What is true of it
G♯ up a perfect fourth is C♯: 5 half steps, and 4 letters counting both ends.
Turn it upside down — put the G♯ 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 G♯
G♯ → Aminor second · dissonanceG♯ → A♯major second · dissonanceG♯ → Bminor third · imperfect consonanceG♯ → B♯major third · imperfect consonanceG♯ → C𝄪augmented fourth · dissonanceG♯ → Ddiminished fifth · dissonanceG♯ → D♯perfect fifth · perfect consonanceG♯ → Eminor sixth · imperfect consonanceG♯ → E♯major sixth · imperfect consonanceG♯ → F♯minor seventh · dissonanceG♯ → F𝄪major seventh · dissonance