interval
G perfect fourth
GlowerCupperP45 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 → A♭minor second · dissonanceG → Amajor second · dissonanceG → B♭minor third · imperfect consonanceG → Bmajor third · imperfect consonanceG → C♯augmented fourth · dissonanceG → D♭diminished fifth · dissonanceG → Dperfect fifth · perfect consonanceG → E♭minor sixth · imperfect consonanceG → Emajor sixth · imperfect consonanceG → Fminor seventh · dissonanceG → F♯major seventh · dissonance