interval
E major seventh
ElowerD♯upperM711 half steps
Eleven half steps: a half step short of the octave, which is why it leans on it.
On the keyboard
What is true of it
E up a major seventh is D♯: 11 half steps, and 7 letters counting both ends.
Turn it upside down — put the E on top — and it becomes a minor second. The two numbers always add to nine, and the two sizes to twelve.
It is a dissonance.
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 → Bperfect fifth · perfect consonanceE → Cminor sixth · imperfect consonanceE → C♯major sixth · imperfect consonanceE → Dminor seventh · dissonance