interval
E perfect fifth
ElowerBupperP57 half steps
Seven half steps. Stack twelve of them and you land back where you started, give or take a comma.
On the keyboard
What is true of it
E up a perfect fifth is B: 7 half steps, and 5 letters counting both ends.
Turn it upside down — put the E on top — and it becomes a perfect fourth. The two numbers always add to nine, and the two sizes to twelve.
It is a perfect consonance.
Every interval on E
E → Fminor second · dissonanceE → F♯major second · dissonanceE → Gminor third · imperfect consonanceE → G♯major third · imperfect consonanceE → Aperfect fourth · perfect consonanceE → A♯augmented fourth · dissonanceE → B♭diminished fifth · dissonanceE → Cminor sixth · imperfect consonanceE → C♯major sixth · imperfect consonanceE → Dminor seventh · dissonanceE → D♯major seventh · dissonance